installation & servicing instructions - heating spares ltd

Supplied By www.heating spares.co Tel. 0161 620 6677

Installation & Servicing Instructions

THESE INSTRUCTIONSTO BE RETAINEDBY USER 0694


Contents

Design principles and operating sequence Page1.1 Principle components 41.2 Mode of operation (at rest) 41.3 Mode of operation (heating) 41.4 Mode of operation (DHW) 41.5 Safety devices 4

Technical data Page2.1 Central heating 52.2 Domestic hot water 52.3 Gas pressure 52.4 Expansion vessel 52.5 Dimensions 52.6 Clearances 52.7 Connections 52.8 Electrical 52.9 Flue details 52.10 Efficiency 52.11 Pump duty 62.12 Appliance 6

General requirements (UK) Page3.1 Related documents 73.2 Location of appliance 73.3 Gas supply 73.4 Flue system 73.5 Air supply 73.6 Water circulation 73.6.1 Pipework 83.6.2 Automatic by-pass 83.6.3 Drain cocks 83.6.4 Air release points 83.6.5 Expansion vessel 83.6.6 Filling point 83.6.7 Low pressure sealed system 83.6.8 Frequent filling 83.7 Electrical supply 83.8 Showers 83.9 Mounting on a combustible surface 93.10 Timber framed building 93.11 Inhibitors 9

Installation Page4.1 Delivery 104.2 Contents 104.3 Unpacking 104.4 Preparation for mounting the appliance 104.5 Fitting the flue 104.5.1 Concentric horizontal flue 104.5.2 Concentric vertical flue 114.6 Connecting the gas and water 124.6.1 Gas 124.6.2 Flow and return 124.6.3 Cold water inlet 124.6.4 Hot water outlet 124.6.5 Safety valve 124.6.6 Condense pipe 124.7 Electrical connections 134.7.1 Casing removal 134.7.2 Appliance terminal block 134.7.3 Connecting the mains (230V) input 13

Commissioning Page5.1 Gas supply installation 145.2 The heating system 145.3 Initial filling of the system 145.4 Initial flushing 145.5 Filling the hot water system 145.6 Pre-operation checks 145.7 Initial lighting 145.7.1 Checking burner pressures 145.8 Final flushing of the heating system 145.8.1 Inhibitors 145.9 Setting the boiler operating temperature 145.9.1 Setting the DHW temperature 155.10 Setting the system design pressure 155.11 Regulating the hot water 155.11.1 Changing the flow restrictor 155.11.2 Regulating the central heating system 155.12 Final checks 155.13 Instructing the user 155.14 Technical assistance 15

Servicing instructions Page6.1 General 166.2 Routine annual servicing 166.3 Replacement of components 166.4 Component removal procedure 166.5 Pump assembly 166.6 Safety valve 166.7 Automatic air release valve 166.8 Water pressure switch 176.9 Pressure gauge 176.10 Primary thermistor 176.11 High limit thermostat 176.12 PCB 176.13 Gas valve 176.14 Integral time switch 186.15 Electrode, burner thermostat, burner & injectors 186.16 Flue fan 186.17 Main heat exchanger 196.18 Air pressure switch 196.19 Flow restrictor 196.20 DHW flow switch 196.21 DHW heat exchanger 206.22 Valve actuator 206.23 Divertor valve cartridge 206.24 DHW thermistor 206.25 Automatic by-pass 206.26 DHW non-return valve 206.27 Expansion vessel 206.27.1 Expansion vessel removal (with sufficient clearance above) 206.27.2 Expansion vessel removal (with insufficient clearance above) 216.28.1 Latent heat collector 216.28.2 Dismantling the latent heat collector 216.29 Condense trap removal 21

Checks, adjustments and fault finding page7.1 Checking appliance operation 227.2 Appliance mode of operation 227.2.1 Selector switch in the OFF position 227.2.2 Selector switch in the hot water only position 227.2.3 Selector switch in the heating & hot water position 227.2.4 Appliance functions 227.2.5 DHW mode 227.2.6 Heating mode 237.3 Checking & adjusting burner pressure 247.3.1 Setting the maximum burner pressure 247.3.2 Setting the minimum burner pressure 247.3.3 Setting the minimum CH output 247.4 Combustion analysis test 247.5 Checking the expansion vessel 257.6 External faults 257.6.1 Installation faults 257.7 Electrical checks 257.7.1 Earth continuity test 257.7.2 Short circuit check 257.7.3 Polarity check 257.7.4 Reversed polarity or supply fault 267.7.5 Resistance to earth check 267.8 Fault finding 267.8.1 Replacing the main PCB 267.9 Fault codes 267.10 Fault finding 27-32

Wiring diagrams Page8.1 External wiring 338.2 Typical control applications 338.3 Room thermostat 338.4 Other controls 33Functional diagram 34

L.P.G. instructions Page10.1 Related documents 3510.2 Technical data 3510.3 Converting the appliance gas supply 3510.4 Gas supply 3510.5 Gas supply installation 3510.6 Checking & adjusting burner pressure 3510.6.1 Setting the maximum burner pressure 3510.6.2 Setting the minimum burner pressure 35

Supplied By www.heating spares.co Tel. 0161 620 6677 3

INTRODUCTION

Fig.1 General Layout

1 Discharge valve2 Gas valve3 Modulator coil4 Pressure switch5 Condense trap6 Ignition transformer7 Expansion vessel8 Electrode9 Main burner10 Main heat exchanger11 Latent heat collector12 Flue gas analysis test point13 Flue outlet14 Air intake15 Differential pressure switch16 Silicone pressure tube (-)17 Silicone pressure tube (+)18 Fan assembly19 CH NTC sensor20 High limit thermostat21 Combustion chamber22 Condensate pressure switch23 Auto air vent (AAV)24 Pump25 DHW flow switch26 DHW sensor27 Domestic hot water heat exchanger28 Diverter valve motor29 Pressure gauge30 DHW position31 Mode selector switch32 Fault indicator led33 CH position34 Timeclock

The PRO Combi HE range of appliances is comprised of2 models of high-efficiency combination boiler with inputsto heating & DHW of 25, 29 kW respectively. Each appli-ance - by design - incorporates electronic ignition, circu-lating pump, expansion vessel, safety valve, pressuregauge and automatic by-pass.

The PRO Combi HE range is produced as room sealed,category II2H3P appliances, suitable for internal wallmounting applications only. They are provided with a fan

powered flue outlet with an annular coaxial combustion airintake that can be rotated - horizontally - through 360degrees for various horizontal or vertical applications. ThePRO Combi HE range is approved for use with C12 & C32type flue applications.These appliances are designed for use with a sealedsystem only; consequently they are not intended for useon open vented systems

Fig. 1

29 30 31 33 3432


SECTION 1 DESIGN PRINCIPLES AND OPERATING SEQUENCE

Fig. 2

1.1 PRINCIPLE COMPONENTS● A fully integrated electronic control board fea-

turing electronic temperature control, anti-cy-cle control, pump over-run, LED fault indicator,full gas modulation.

● Low-water-content, copper heat exchanger.● Electronic ignition with flame supervision.● Integral high-head pump.● Fan.● Air pressure switch.● Expansion vessel.● Water pressure switch.● Two-stage gas valve.● Pressure gauge.● Safety valve.● Condense switch.

1.2 MODE OF OPERATION (at rest)When the appliance is at rest and there are norequests for heating or DHW, the following func-tions are active:● Frost-protection system: the frost-protection

system protects the appliance against the riskof frost damage. Should the temperature of theappliance fall to 5 °C, the boiler will function inthe heating mode at minimum power until itreaches 35 °C.

● Anti-block function: the anti-block function ena-bles the pump and divertor valve actuator, to beenergised for short periods, when the appli-ance has been inactive for more than 19-hours.

1.3 MODE OF OPERATION (Heating)When there is a request for heat via the time clockand/or any external control, the pump and fan arestarted, the fan will then prove the air pressureswitch. At this point an ignition sequence isenabled.

Ignition is sensed by the electronic circuitry toensure flame stability at the burner. Once suc-cessful ignition has been achieved, the electroniccircuitry increases the gas rate to 75% for aperiod of 15 minutes. Thereafter, the boiler’soutput will either be increase to maximum ormodulate to suit the set requirement.

When the appliance reaches the desired tem-perature the burner will shut down and the boilerwill perform a three-minute anti-cycle (timer de-lay).

When the request for heat has been satisfied theappliance pump and fan may continue to operateto dissipate any residual heat within the appli-ance.

1.4 MODE OF OPERATION (DHW)When there is a request for DHW via a hot wateroutlet or tap, the pump and fan are started, the fanwill then prove the air pressure switch. At thispoint an ignition sequence is enabled.

Ignition is sensed by the electronic circuitry toensure flame stability at the burner. Once suc-cessful ignition has been achieved, the electroniccircuitry increases the gas rate to maximum orwill modulate output to stabilise the temperature.

In the event of the appliance exceeding thedesired temperature the burner will shut downuntil the temperature drops.

When the request for DHW has been satisfied theappliance pump and fan may continue to operateto dissipate any residual heat within the appli-ance.

1.5 SAFETY DEVICESWhen the appliance is in use, safe operation isensured by:● A water pressure switch that monitors system

water pressure and will deactivate the pump,fan and burner should the system water pres-sure drop below the rated tolerance.

● A high limit thermostat that over-rides the tem-perature control circuit to prevent or interruptthe operation of the burner.

● An air pressure switch that requires the fan toprove operation before the gas valve is ener-gised.

● A pressure switch that interrupts the operationof the appliance if the condense pipe becomesblocked.

● A safety valve which releases excess pressurefrom the primary circuit.

Automaticby-pass

DHW nonreturn valve

Safety valve

DHWtemperature

sensor

Divertervalve motor

Waterpressureswitch

AAV

latent heatcollector

Flueoutlet

Airintake

Pressureswitch

Main heatexchanger

Gas valve

Mainburner

CH NTCsensor

Expansionvessel

PumpDHW heatexchanger

DHWflow switch

CHreturn

CHflow

DHWoutlet

Domestic coldwater inlet


SECTION 2 TECHNICAL DATA

Ref. Condition 15 °C , 1013,25 mbar, dry gasNOTE: L.P.G. data refer to section 10

85 HE 100 HE

2.1 Central heating

Heat input (kW) 25.00 29.00

Maximum heat output@ 80/60 °C (kW) 24.35 28.30

Minimum heat output@ 80/60 °C (kW) 14.25 14.28

Maximum heat output@ 50/30 °C (kW) 25.90 29.93

Minimum heat output@ 50/30 °C (kW) 14.85 14.75

Minimum working pressure 0.5 bar 0.5 bar

Maximum working pressure 2.7 bar 2.7 bar

Minimum flow rate 350 l/h 350 l/h

2.2 Domestic hot water

Minimum output (kW) 9.50 9.90

Flow rate (35 °C rise) 10.2 l/min 11.9 l/min

Maximum inlet pressure 6.0 bar 6.0 bar

Minimum inlet working pressure 0.15 bar 0.15 bar

Minimum flow rate 2 l/min. 2 l/min.

2.3 Gas pressures

Inlet pressure G20 20.0 mbar 20.0 mbar

Maximum burner pressure 9.40 mbar 9.20 mbar

Minimum burner pressure (central heating) 3.50 mbar 2.70 mbar

Minimum burner pressure (domestic hot water) 1.50 mbar 1.20 mbar

Gross rate (central heating, max - min) 2.64 - 1.59 m3/h 3.07 - 1.59 m3/h

Injectors size 12 x 1.35 mm 14 x 1.35 mm

2.4 Expansion vessel

Capacity 8 litres 10 litres

Maximum system volume 76 litres 91 litres

Pre-charge pressure 1.0 bar 1.0 bar

2.5 Dimensions

Height 780 mm 780 mm

Width 400 mm 450 mm

Depth 332 mm 332 mm

Dry weight 40 kg 44 kg

2.6 Clearances

Sides 12 mm 12 mm

Top 150 mm from casing or 25 mm above flue elbow, whichever is applicable

Bottom 150 mm 150 mm

Front 600 mm 600 mm

2.7 Connections

Flow & return 22 mm 22 mm

Hot & cold water connections 15 mm 15 mm

Gas 15 mm 15 mm

Safety valve 15 mm 15 mm

Condense 21 mm 21 mm

2.8 Electrical

Voltage 230V/~ 50hz 230V/~ 50hz

Power consumption 153 W 153 W

Internal fuse 2 A 2 A

External fuse 3 A 3 A

2.9 Flue details (concentric)

Maximum horizontal flue length (60/100mm) 4.5 m 4.0 m

Maximum vertical flue length (60/100mm) 5.5 m 5.0 m

2.10 EfficiencySEDBUK 86.9 Band “B” 86.7 Band “B”


2.11 PUMP DUTYFig. 3 shows the flow rate available - after allowing for pressure loss through the appliance - for systemrequirements. When using this graph, apply only the pressure loss of the system. The graph is based on a20 ºC temperature differential.

Fig. 4

SECTION 3 GENERAL REQUIREMENTS

Key Location Minimum distance

A Below an opening (window, air-brick, etc.) 300 mmB Above an opening (window, air-brick, etc.) 300 mmC To the side of an opening (window, air-brick, etc.) 300 mmD Below gutter, drain-pipe, etc. 25 mmE Below eaves 25mmF Below balcony, car-port roof, etc. 25 mmG To the side of a soil/drain-pipe, etc. 25 mmH From internal/external corner or boundary 300 mmI Above ground, roof, or balcony level 300 mmJ From a surface or boundary facing the terminal 1200 mmK From a terminal facing a terminal 1200 mmL From an opening in the car-port into the building 1200 mmM Vertically from a terminal on the same wall 1500 mmN Horizontally from a terminal on the same wall 300 mmP From a structure to the side of the vertical terminal 500 mmQ From the top of the vertical terminal to the roof flashing As determined by the fixed collar

of the vertical terminal

2.12 ApplianceNOx 94 ppm - 166 mg/kWh 92 ppm - 162 mg/kWhCO (max-min) 80 ppm - 80 ppm 100 ppm - 60 ppmCO2 (max-min) 6.75 - 3.90 % 7.05 - 3.50 %CO/CO2 ratio (max) 0.001 to 1 0.001 to 1CO/CO2 ratio (min) 0.002 to 1 0.002 to 1

85 HE 100 HE

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

4,5

5,0

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300

first speed

second speed

third speed

85 HE - 100 HE


This appliance must be installed by a competentperson in accordance with the Gas Safety (Instal-lation & Use) Regulations.

3.1 RELATED DOCUMENTSThe installation of this boiler must be in accord-ance with the relevant requirements of the GasSafety (Installation & Use) Regulations, the localbuilding regulations, the current I.E.E. wiringregulations, the bylaws of the local water under-taking, the Building Standards (Scotland) Regu-lation and Building Standards (Northern Ireland)Regulations.It should be in accordance also with any relevantrequirements of the local authority and the rel-evant recommendations of the following BritishStandard Codes of Practice.

3.2 LOCATION OF APPLIANCEThe appliance may be installed in any room orinternal space, although particular attention isdrawn to the requirements of the current I.E.E.wiring regulations and in Scotland, the electricalprovisions of the Building Regulations, with re-spect to the installation of the appliance in a roomor internal space containing a bath or shower.

When an appliance is installed in a room or internalspace containing a bath or shower, the applianceor any control pertaining to it must not be withinreach of a person using the bath or shower.The location chosen for the appliance must permitthe provision of a safe and satisfactory flue andtermination. The location must also permit anadequate air supply for combustion purposesand an adequate space for servicing and aircirculation around the appliance. Where the in-stallation of the appliance will be in an unusuallocation special procedures may be necessary,BS 6798 gives detailed guidance on this aspect.A compartment used to enclose the appliancemust be designed and constructed specificallyfor this purpose. An existing compartment/cup-board may be utilised provided that it is modifiedto suit.Details of essential features of compartment/cupboard design including airing cupboard instal-lations are given in BS 6798. This appliance is notsuitable for external installation.

3.3 GAS SUPPLYThe gas meter - as supplied by the gas supplier- must be checked to ensure that it is of adequatesize to deal with the maximum rated input of allthe appliances that it serves. Installation pipesmust be fitted in accordance with BS 6891.Pipe work from the meter to the appliance mustbe of adequate size. Pipes of a smaller size thanthe appliance gas inlet connection must not beused. The installation must be tested for sound-ness in accordance with BS6891.If the gas supply serves more than one appliance,it must be ensured that an adequate supply ismaintained to each appliance when they are inuse at the same time.

3.4 FLUE SYSTEMThe terminal should be located where the disper-sal of combustion products is not impeded andwith due regard for the damage and discolorationthat may occur to building products located nearby.The terminal must not be located in a place whereit is likely to cause a nuisance (see fig. 4).Water vapour will condense on leaving the termi-nal and the effect of such pluming must beconsidered.

BS 5440 PART 1 FLUES

BS 5440 PART 2 FLUES & VENTILATION

BS 5449 PART 1 FORCED CIRCULATION HOT WATER SYSTEMS

BS 5546 INSTALLATION OF GAS HOT WATER SUPPLIES FOR DOMESTIC PURPOSES(2ND FAMILY GASES)

BS 6798 INSTALLATION OF BOILERS OF RATED INPUT NOT EXCEEDING 60kW

BS 6891 LOW PRESSURE INSTALLATION PIPES

BS 7074 PART 1 APPLICATION, SELECTION AND INSTALLATION OF EXPANSION VESSELS ANDANCILLARY EQUIPMENT FOR SEALED WATER SYSTEMS

If installed less than 2m above a pavement orplatform to which people have access (includingbalconies or flat roofs) the terminal must beprotected by a guard of durable material. Theguard must be fitted centrally over the terminal.Refer to BS 5440 Part 1, when a terminal is sitedless than 1m below a plastic gutter, or less than500mm below a painted surface, a suitable onemetre long heat shield should be fitted.

3.5 AIR SUPPLYThe following notes are intended for generalguidance only.This appliance is a room-sealed, fan-flued boiler,consequently it does not require a permanent airvent for combustion air supply.When installed in a cupboard or compartment,ventilation for cooling purposes is also not re-quired.

3.6 WATER CIRCULATIONDetailed recommendations are given in BS 5449Part 1 and BS 6798. The following notes are forgeneral guidance only.


Fig. 5a

3.6.7 LOW PRESSURE SEALED SYSTEMAn alternative method of filling the system wouldbe from an independent make-up vessel or tankmounted in a position at least 1 metre above thehighest point in the system and at least 5 metresabove the boiler (see fig. 5a).The cold feed from the make-up vessel or tankmust be fitted with an approved non-return valveand stopcock for isolation purposes. The feedpipe should be connected to the return pipe asclose to the boiler as possible.

3.6.8 FREQUENT FILLINGFrequent filling or venting of the system may beindicative of a leak. Care should be taken duringthe installation of the appliance to ensure allaspects of the system are capable of withstand-ing pressures up to at least 3 bar.

3.7 ELECTRICAL SUPPLYThe appliance is supplied for operation on 230V@ 50Hz electrical supply; it must be protectedwith a 3-amp fuse. The method of connection tothe mains electricity supply must allow for com-plete isolation from the supply. The preferredmethod is by using a double-pole switch with acontact separation of at least 3mm. The switchmust only supply the appliance and its corre-sponding controls, i.e. time clock, room thermo-stat, etc. Alternatively an un-switched shutteredsocket with a fused 3-pin plug both complyingwith BS 1363 is acceptable.

3.8 SHOWERSIf the appliance is intended for use with a shower,the shower must be thermostatically controlledand be suitable for use with a combination boiler.

3.6.1 PIPEWORKIt is recommended that copper tubing to BS 2871Part 1 is used in conjunction with soldered capil-lary joints.Where possible pipes should have a gradient toensure air is carried naturally to air release pointsand that water flows naturally to drain cocks.Except where providing useful heat, pipes shouldbe insulated to avoid heat loss and in particular toavoid the possibility of freezing. Particular atten-tion should be paid to pipes passing throughventilated areas such as under floors, loft spaceand void areas.

3.6.2 AUTOMATIC BY-PASSThe appliance has a built-in automatic by-pass.However it may be necessary to fit an externalbypass should the design of the heating systemrequire such. In any case, the design of thesystem should be such that it prevents boiler‘cycling’.

3.6.3 DRAIN COCKSThese must be located in accessible positions tofacilitate draining of the appliance and all waterpipes connected to the appliance. The draincocks must be manufactured in accordance withBS 2879.

3.6.4 AIR RELEASE POINTSThese must be positioned at the highest points inthe system where air is likely to be trapped. Theyshould be used to expel trapped air and allowcomplete filling of the system.

3.6.5 EXPANSION VESSELThe appliance has an integral expansion vesselto accommodate the increased volume of waterwhen the system is heated. It can accept up to 8litres (25kW) or 10 litres (29 kW) of expansion fromwithin the system, generally this is sufficient,however if the system has an unusually high watercontent, it may be necessary to provide additionalexpansion capacity (see 6.19).

3.6.6 FILLING POINTAn approved method for initial filling of the systemand replacing water lost during servicing etc. isrequired (see fig. 5). This method of filling mustcomply with the current Water Supply (WaterFittings) Regulations 1999 and Water Bylaws2000 (Scotland).

Fig. 5

control valve

temporaryconnection

control valve

supply pipe

double checkvalve

flow/returnpipe

Make-up vesselor tank

Automaticair-vent

Non-returnvalve

Stopcock

5.0

met

res

min

imum

Heatingreturn


3.9 MOUNTING ON A COMBUSTIBLE SURFACEIf the appliance is to be fitted on a wall ofcombustible material, a sheet of fireproof mate-rial must protect the wall.

3.10 TIMBER FRAMED BUILDINGIf the appliance is to be fitted in a timber framedbuilding, it should be fitted in accordance with theInstitute of Gas Engineers publication (IGE/UP/7) ‘Guide for Gas Installations in Timber FrameBuildings’.

3.11 INHIBITORSIt is recommend that an inhibitor - suitable for usewith copper and aluminium heat exchangers - isused to protect the boiler and system from theeffects of corrosion and/or electrolytic action.The inhibitor must be administered in strict ac-cordance with the manufacturers instructions*.

*Water treatment of the complete heating system- including the boiler - should be carried out inaccordance with BS 7593 and the DomesticWater Treatment Association’s (DWTA) code ofpractice.

Fig. 6a

Fig. 6


Using the template provided, mark and drill a115mm hole for the passage of the flue pipe. Thehole should be drilled level to ensure any con-dense fluid that forms will drain back to the boiler.The fixing holes for the wall-mounting bracketshould now be drilled and plugged, an appropri-ate type and quantity of fixing should be used toensure that the bracket is mounted securely.Once the bracket has been secured to the wall,mount the appliance onto the bracket.

FITTING THE HORIZONTAL FLUE KITCarefully measure the distance from the centre ofthe appliance flue outlet to the edge of the fin-ished outside wall (dimension X). Add 65mm todimension X to give you dimension Y (see fig 7A).Measure dimension Y from the terminal end ofthe concentric flue pipe and cut off the excessfrom the 100mm pipe ensuring any burrs areremoved. Using the cut-off piece of 100mm pipeas a guide, mark and cut the same length of pipefrom the inner 60mm pipe (the 60mm shouldalways project past the 100mm pipe by 30mm).Pass the concentric flue pipe through the previ-ously drilled hole. Fit the flue bend to the boilerflue outlet and insert the concentric flue pipe intothe flue bend ensuring the correct seal is made.Using the clamps, gaskets, and screws supplied,secure the flue bend to the appliance flue spigotand the flue terminal.

NOTEFit the internal (White) trim to the flue assemblyprior to connecting the flue pipe to the bend.

Fig. 7

Boiler

outerclamp

Terminal orextension

SECTION 4 INSTALLATION

4.1 DELIVERYDue to the weight of the appliance it may be necessaryfor two people to lift and attach the appliance to itsmounting. The appliance is contained within a heavy-duty cardboard carton. Lay the carton on the floor withthe writing the correct way up.

4.2 CONTENTSContained within the carton is:● the boiler● the wall bracket● appliance template● an accessories pack containing appliance serv-

ice connections and washers● the instruction pack containing the installation

& servicing instructions, user instructions,Benchmark logbook, guarantee registration cardand a 3-amp fuse.

4.3 UNPACKINGAt the top of the carton pull both sides open - donot use a knife - unfold the rest of the carton fromaround the appliance, carefully remove all pro-tective packaging from the appliance and lay theaccessories etc. to one side. Protective glovesshould be used to lift the appliance, the applianceback-frame should be used for lifting points.

4.4 PREPARATION FOR MOUNTING THE APPLI-ANCEThe appliance should be mounted on a smooth,vertical, non-combustible surface, which must becapable of supporting the full weight of the appli-ance. Care should be exercised when determin-ing the position of the appliance with respect tohidden obstructions such as pipes, cables, etc.When the position of the appliance has beendecided - using the template supplied - carefullymark the position of the wall- mounting bracket(see fig. 6) and flue-hole (if applicable).

4.5 FITTING THE FLUEThe top flue outlet permits both horizontal andvertical flue applications to be considered.

4.5.1 CONCENTRIC HORIZONTAL FLUE(For concentric vertical flue, see section 4.5.2).

The appliance flue outlet elbow can be rotatedthrough 360º on its vertical axis. In addition theflue may be extended from the outlet elbow in thehorizontal plane (see 2.9). A reduction must alsobe made to the maximum length (see tablebelow) when additional bends are used.

Bend Reduction in maximum flue length for each bend

45º bend 0.5 metre

90º bend 1.0 metre

Reduction for additional bends

Part No. Description Min-Max Length

489 Telescopic flue terminal kit 350/500mm491 Horizontal flue kit for use with 1000 mm

add. bends & extensions492 0.5m extension 500 mm493 1.0m extension 1000 mm494 2.0m extension 2000 mm495 45º bend (pair) N/A496 90º bend N/A499 Wall bracket N/A

Horizontal flue terminals and accessories


Using the dimensions given in fig. 9 as a refer-ence, mark and cut a 107mm hole in the ceilingand/or roof.

4.5.1.1 EXTENDING THE FLUEConnect the bend - supplied with the terminal kit- to the top of the boiler using clamp (supplied)see fig. 7. The additional bends & extensions havepush-fit connections, care should be taken toensure that the correct seal is made when as-sembling the flue system. Connect the requirednumber of flue extensions or bends (up to themaximum equivalent flue length) to the flue ter-minal (see fig. 7 & 8).The hole should be drilled level to ensure that anycondense fluid drains back to the appliance.NOTEWhen cutting an extension to the required length,you must ensure that the excess is cut from theplain end of the extension (see fig. 7 & 8). Re-move any burrs, and check that all seals are lo-cated properly. You must ensure that the entireflue system is properly supported and connected.Seal the flue assembly to the wall using cementor a suitable alternative that will provide satisfac-tory weatherproofing.

4.5.2 CONCENTRIC VERTICAL FLUEThe vertical flue terminal can be connected di-rectly to the appliance flue outlet. Alternatively,

Fig. 9

Bend Reduction in maximum flue length for each bend

45º bend 0.5 metre

90º bend 1.0 metre

Reduction for bends

Part No. Description Min-Max Length

490 Vertical flue terminal497 Pitched roof flashing plate N/A498 Flat roof flashing plate N/A492 0.5m extension 500 mm493 1.0m extension 1000 mm494 2.0m extension 2000 mm495 45º bend (pair) N/A496 90º bend N/A499 Wall bracket N/A

Vertical flue terminal and accessories

145

Fig. 8

Fig. 7a

FLUE RESTRICTOR RING (horizontal flue)To ensure maximum efficiency of the appliance,it may be necessary to fit one of the suppliedflue restrictor rings to the appliance flue outlet(see tables below).

Total flue length Restrictor required

Less than 1.2 metre 82.5mm diameter (fitted)

Less than 3.0 metres 88mm diameter

Less than 4.5 metres not required


Less than 2.0 metres 84mm diameter (fitted)


100 HE

an extension or bend can be connected to theappliance flue outlet if desired (see 4.4.2), how-ever if additional bends are fitted, a reductionmust be made to the maximum flue length (seetable below).

FLUE RESTRICTOR RING (vertical flue)To ensure maximum efficiency of the appliance,it may be necessary to fit one of the suppliedflue restrictor rings to the appliance flue outlet(see tables below).


Less than 2.0 metre 82.5mm diameter (fitted)

Less than 4.0 metres 88mm diameter


85 HE


Less than 2.8 metres 84mm diameter (fitted)


100 HE

85 HE


Fit the appropriate flashing plate to the roof andinsert the vertical flue terminal through the flash-ing plate from the outside, ensuring that the collaron the flue terminal fits over the flashing.The fixing holes for the wall-mounting bracketshould now be drilled and plugged, an appropri-ate type and quantity of fixing should be used toensure that the bracket is mounted securely.Once the bracket has been secured to the wall,mount the appliance onto the bracket.

IMPORTANTThe vertical flue terminal cannot be cut; thereforeit may be necessary to adjust the height of theappliance to suit or use a suitable extension.Connect the vertical flue assembly to the boiler fluespigot using the 60mm & 100mm clips, gaskets &screws (supplied), ensuring the correct seal ismade. The flue support bracket (supplied with thevertical flue kit) can now be fitted.If the vertical flue requires extension/s or addi-tional bend/s, connect the required number offlue extensions or bends (up to the maximumequivalent flue length) between the boiler andvertical flue assembly (see fig. 8).Ensure that any horizontal sections of the fluesystem have a minimum 1º fall back to the boiler(17mm per 1000mm).

NOTEWhen cutting an extension to the required length,you must ensure that the excess is cut from theplain end of the extension (see fig. 8). Removeany burrs, and check that any seals are locatedproperly. You must ensure that the entire fluesystem is properly supported and connected.

4.6 CONNECTING THE GAS AND WATERThe appliance is supplied with an accessory packthat includes service valves.The service valves are of the compression type.The accessory pack contains sealing washers’ etc,for use with the service valves. When connectingpipe work to the valves, tighten the compressionend first then insert the sealing washers beforetightening the valve to the appliance.

NOTEIt will be necessary to hold the valve with onespanner whilst tightening with another

4.6.1 GAS (fig. 6 & 10)The appliance is supplied with a 15mm servicevalve, connect a 15mm pipe to the inlet of thevalve and tighten both nuts.NOTEIt will be necessary to calculate the diameter ofthe gas supply pipe to ensure the appliance hasan adequate supply of gas.

4.6.2 FLOW & RETURN (fig. 6 & 10)The appliance is supplied with 22mm servicevalves for the flow and return connections, con-nect a 22mm pipe to the inlet of each valve andtighten both nuts.

NOTEDepending on system requirements, it may nec-essary to increase the size of the flow & return pipework after the service valve connections.

4.6.3 COLD WATER INLET (fig. 6 & 10)The appliance is supplied with a 15mm stopcock,connect a 15mm pipe to the inlet of the stopcockand tighten both nuts.

4.6.4 HOT WATER OUTLET (fig. 6 & 10)The appliance is supplied with a 15mm outletconnection, connect a 15mm pipe to the outletconnection and tighten both nuts.

4.6.5 SAFETY VALVE (fig. 6 & 10)Connect the safety valve pipe to the safety valveoutlet and tighten. The discharge pipe must havea continuous fall away from the appliance tooutside and allow any water to drain away therebyeliminating the possibility of freezing. The dis-charge pipe must terminate in a position where anywater - possibly boiling - discharges safely withoutcausing damage or injury, but is still visible.

4.6.6 CONDENSE PIPE (fig. 6 & 10)During normal operation the boiler produces con-dense which is collected in a trap located in thelower part of the boiler. A flexible pipe (condenseoutlet pipe) is connected to the outlet of the trap.The flexible pipe must be connected to a plasticwaste pipe only. The plastic waste pipe must havea minimum of a 3º fall towards the drain. Anyexternal run of pipe should be insulated to preventthe risk of freezing.

CONNECTING THE CONDENSATE OUTLETGently pull the condense outlet pipe down from itslocation inside the boiler until approximately itprotrudes from the underside of the boiler. Con-nect a suitable plastic (not copper) pipe (no lessthan 21mm diameter) to the outlet pipe and ensureit discharges in accordance with local buildingregulations or other rules in force.

Fig. 10

flow returngasDHWoutlet

DHWinlet

condense


4.7 ELECTRICAL CONNECTIONSThe boiler is supplied with a 2-metre fly-lead. Thislead can be used for connection to the electricalsupply. Connect the fly-lead to a fused plug orfused isolator in the following way:● brown wire to LIVE supply● blue wire to NEUTRAL supply● green/yellow to EARTH connection.

Insert the supplied 3-AMP fuse into the fusedisolator or fused plug.Should the fly-lead be unsuitable, refer to 4.7.3for details on how to connect the electrical supplydirectly to the boiler.The electrical supply must be as specified insection 3/3A. A qualified electrician should con-nect the appliance to the electrical supply. Ifcontrols - external to the appliance - are required,a competent person must undertake the designof any external electrical circuits, please refer tosection 8 for detailed instructions. ANY EXTER-NAL CONTROL OR WIRING MUST BE SERVEDFROM THE SAME ISOLATOR AS THAT OFTHE APPLIANCE. The supply cable from theisolator to the appliance must be 3-core flexiblesized 0.75mm to BS 6500 or equivalent. Wiring tothe appliance must be rated for operation incontact with surfaces up to 90 ºC.

4.7.1 CASING REMOVALTo gain internal access to the appliance you must firstremove the casing, proceed as outlined below:● locate and unscrew the 3-screws (A) that se-

cure the outer casing to the appliance (see fig.11)

● lift the casing upward to disengage it from thetop locating hooks and then remove

● store the casing and screws safely until re-quired. Re-fit in the reverse order

● gently lower the control fascia until it rests.

4.7.2 APPLIANCE TERMINAL BLOCKThe appliance terminal block is located on theleft side of the control fascia (see fig. 11). Locateand remove the screw that secures the terminalblock cover.

NOTEThe appliance comes with a factory fitted clockto allow basic operation of the boiler. If it is antici-pated that additional controls - such as a room

thermostat - will be required please refer to thewiring diagrams in section 8 for more detailedinformation.

4.7.3 CONNECTING THE MAINS (230V) INPUT (seefig. 12)Lift the terminal block cover as described in 4.7.2.Pass the cable through the cable anchorage point.At the terminal block on the extreme left, thereare 3 terminals from left to right they are:

LIVE - NEUTRAL - EARTH

Connect the supply cable wires (LIVE, NEUTRAL& EARTH) to their corresponding terminals on theappliance terminal block (see fig. 13). Ensure thatthe EARTH wire is left slightly longer than theothers, this will prevent strain on the EARTH wireshould the cable become taut.

The securing screw on the cable anchorageshould now be tightened. This must be donebefore the control fascia is re-fitted in the uprightposition. The appliance casing and screws cannow be re-fitted.

Control panel screws and casing screws

Fig. 11

A

Fig. 12

Fig. 13


5.1 GAS SUPPLY INSTALLATIONInspect the entire installation including the gasmeter, test for soundness and purge. Refer to BS6891 for specific instruction.

5.2 THE HEATING SYSTEMThe appliance contains components that maybecome damaged or rendered inoperable by oilsand/or debris that are residual from the installa-tion of the system, consequently it is essentialthat the system be flushed in accordance with thefollowing instructions.

5.3 INITIAL FILLING OF THE SYSTEMEnsure both flow and return service valves areopen, remove appliance casing as described in4.7.1, identify the automatic air release valve andloosen the dust cap by turning the cap anti-clockwise one full turn. IMPORTANT, THEREARE NO MANUAL AIR RELEASE VALVES LO-CATED ON THE APPLIANCE. Ensure all manualair release valves located on the heating systemare closed. Connect the filling loop (not supplied)and slowly proceed to fill the system. As waterenters the system the pressure gauge will beginto rise. Once the gauge has reached 1 BAR closethe filling loop and begin venting all manual airrelease valves, starting at the lowest first. It maybe necessary to go back and top-up the pressureuntil the entire system has been filled. Inspect thesystem for water soundness, rectifying any leaks.

5.4 INITIAL FLUSHINGThe whole of the heating system must be flushedboth cold and hot as detailed in 5.8. Open allradiator or heating valves and the appliance flow& return service valves. Drain the boiler andsystem from the lowest points. Open the drainvalve full bore to remove any installation debrisfrom the boiler prior to lighting. Refill the boilerand heating system as described in 5.3.

5.5 FILLING THE HOT WATER SYSTEMClose all hot water outlets, turn appliance stop-cock to the normal operating position (fully coun-ter clockwise), slowly open each outlet until airhas been expelled and clear water is discharged.Check pipe-work etc. for water soundness.

5.6 PRE-OPERATION CHECKSBefore attempting the initial lighting of the appli-ance, the following checks must be carried out:● ensure all gas service valves from the meter to

the appliance are open and the supply pipe hasbeen properly purged

● ensure the proper electrical checks have beencarried out, (see 7.7) particularly continuity,polarity and resistance to earth

● ensure the 3 AMP fuse - supplied with theappliance - has been fitted

● ensure the system has been filled, vented andthe pressure set to 1 BAR

● ensure the flue system has been fitted properlyand in accordance with the instructions

● ensure all appliance service valves are open.

SECTION 5 COMMISSIONING

5.7 INITIAL LIGHTINGEnsure the electrical supply to the appliance isswitched on. Move the selector switch to theHeating & Hot Water position, ensure the timeclock is switched to an ‘ON’ position and ensureany other external controls (room thermostat forexample) are also calling for heat.The appliance will now operate in the mode asdescribed in 1.2. Should the appliance fail toignite, refer to 5.6 and/or section 7 (faultfinding).

5.7.1 CHECKING THE BURNER PRESSUREAlthough the burner pressure is factory set, it isnecessary to check it during commissioning. Isolatethe appliance from the electrical supply and attacha suitable manometer to the gas valve outlet test-point (see fig. 14). Light the boiler as described in5.7, turn the Hot Water temperature selector tomaximum, and open fully a DHW outlet (preferablythe bath), allowing the appliance to stabilise.Compare the reading on the manometer with thevalue described in 2.3. If adjustment is required,follow the detailed instructions in section 7 (7.3).Once the burner pressure has been checked, close

the DHW outlet, isolate the appliance from theelectrical supply, remove the manometer andtighten the gas valve outlet test nipple.

5.8 FINAL FLUSHING OF THE HEATING SYSTEMThe system shall be flushed in accordance withBS 7593. Should a cleanser be used, it must besuitable for Copper and Aluminium heat exchang-ers. It shall be from a reputable manufacturer andshall be administered in strict accordance with themanufacturers’ instructions and the DWTA codeof practice.

5.8.1 INHIBITORSSee section 3 “General requirements”.

5.9 SETTING THE BOILER OPERATING TEMPERA-TUREThe flow outlet temperature can be adjusted be-tween 40 ºC - 80 ºC via the Heating thermostatknob (see fig.1).

Fig. 14

Protectivecap

Outlettest-point

Inlettest-point


5.9.1 SETTING THE DOMESTIC HOT WATER TEM-PERATUREThe DHW outlet temperature can be adjustedbetween 40 ºC - 65 ºC via the Hot Water thermo-stat knob (see fig.1).

5.10 SETTING THE SYSTEM DESIGN PRESSUREThe design pressure should be a minimum of 1BAR and a maximum of 1.5 BAR.The actual reading should ideally be 1BAR plusthe equivalent height in metres (0.1 BAR = 1metre) to the highest point in the system abovethe base of the appliance (up to the maximum of1.5 BAR total).N.B. The safety valve is set to lift at 3 BAR/30metres/45 psig.).To lower the system pressure to the requiredvalue, water can be drained from the heatingsystem drain cock or from the boiler drain cock.

5.11 REGULATING THE HOT WATERThe appliance is fitted with a flow rate restrictorthat limits the maximum flow rate that can bedrawn through the appliance.

The restrictor eliminates the need to manuallyadjust the DHW flow rate. However if it is feltnecessary to further increase or decrease theavailable flow rate, spare restrictors are includedin the accessory pack.The spare flow rate restrictors can be fitted toeither increase or decrease the maximum flowrate. The tables above denote the size of restrictorfitted and the spare restrictors supplied in theaccessory pack. Each restrictor is colour-codedto enable identification.

5.11.1 CHANGING THE FLOW RESTRICTORRefer to 6.19 for detailed instruction on changingthe flow restrictor.

5.11.2 REGULATING THE CENTRAL HEATING SYS-TEMFully open all radiator and circuit valves and runthe appliance for both heating and hot water untilheated water is circulating. If conditions are warmremove any thermostatic heads. Adjust radiatorreturn valves and any branch circuit return valvesuntil the individual return temperatures are cor-rect and are approximately equal.

5.12 FINAL CHECKS● ENSURE ALL TEST NIPPLES ON THE APPLI-

ANCE GAS VALVE HAVE BEN TIGHTENED

AND CHECKED FOR SOUNDNESS.● ENSURE THE APPLIANCE FLUE SYSTEM

IS FITTED CORRECTLY AND IS PROPERLYSECURED.

● ENSURE ALL PIPE WORK IS RE-CHECKEDFOR SOUNDNESS.

● RE-FIT APPLIANCE CASING.● COMPLETE BENCHMARK CHECKLIST.

Complete details of the boiler, controls, installa-tion and commissioning in the Benchmark check-list at the back of this book. It is important thatthe Benchmark checklist is correctly completedand handed to the user. Failure to install andcommission the appliance to the manufacturersinstructions may invalidate the warranty.

5.13 INSTRUCTING THE USERHand over all documentation supplied with thisappliance - including these instructions - andexplain the importance of keeping them in a safeplace.Explain to the user how to isolate the appliancefrom the gas, water and electricity supplies, andthe locations of all drain points.Show the user how to operate the appliance andany associated controls correctly.Show the user the location of the filling valve andhow to top-up the system pressure correctly, andshow the location of all manual air release points.Explain to the user how to turn off the appliance forboth long and short periods and advise on thenecessary precautions to prevent frost damage.Explain to the user that for continued safe andefficient operation, the appliance must be serv-iced annually by a competent person.

5.14 TECHNICAL ASSISTANCEShould you require technical advice or assistanceon this product, please contact ‘Heating Services’on 0870 264 1220 or Heating Services, PO BOX167, BRADFORD, BD19 4WL.

9-litre (Orange) 10-litre (Blue) 11-litre (Beige)Spare Fitted Spare

100 HE

8-litre (White) 9-litre (Orange) 10-litre (Blue)Fitted Spare Spare

85 HE


SECTION 6 SERVICING INSTRUCTIONS

6.1 GENERALTo ensure the continued safe and efficient opera-tion of the appliance, it is recommended that it ischecked and serviced at regular intervals.

To ensure correct and safe operation of theappliance, it is essential that any worn or failedcomponent be replaced only with a genuinespare part.

The frequency of servicing will depend upon theparticular installation conditions, but in general,once per year should be adequate.

It is the law that any servicing work is carried out bycompetent person such as an engineer, an approvedservice agent, British Gas, CORGI registered per-sonnel or other suitably qualified personnel.

The following instructions apply to the applianceand its controls, but it should be rememberedthat the central heating and the domestic hotwater systems would also require attention fromtime to time.

6.2 ROUTINE ANNUAL SERVICINGCheck the operation of the appliance and ensureit functions as described in section 7. Comparethe performance of the appliance with its designspecification. The cause of any noticeable dete-rioration should be identified and rectified withoutdelay.Thoroughly inspect the appliance for signs ofdamage or deterioration especially the flue sys-tem and the electrical apparatus.Check and adjust - if necessary - all burnerpressure settings (see section 7.3).Check and adjust - if necessary - the systemdesign pressure (see section 5.10).Carry out an analysis of the flue gases (see 7.4)and visually check the condition of the entire flueassembly. Compare the results with the appli-ance design specification. Any deterioration inperformance must be identified and rectified with-out delay.Ensure both flue venturis are clean and free fromany debris or obstruction.Ensure the burner, main heat exchanger andlatent heat collector are clean and free from anydebris or obstruction.

6.3 REPLACEMENT OF COMPONENTSAlthough it is anticipated that this appliance willgive years of reliable, trouble free service, the lifespan of components will be determined by factorssuch as operating conditions and usage. Shouldthe appliance develop a fault, the fault findingsection will assist in determining which compo-nent is malfunctioning.

6.4 COMPONENT REMOVAL PROCEDURETo remove a component, access to the interior ofthe appliance is essential. Isolate the appliancefrom the electrical supply and remove the fuse.And when necessary, close all service valves on

the appliance, remove the appliance casing asdescribed in section 4.7.1 and drain the watercontent from the appliance via the drain valvelocated at the front of the hydraulic section usingthe tube provided. Ensure some water absorbentcloths are available to catch any residual waterthat may drip from the appliance or removedcomponent. Undertake a complete commission-ing check as detailed in section 5, after replacingany component. ALWAYS TEST FOR GASSOUNDNESS IF ANY GAS CARRYING COM-PONENTS HAVE BEEN REMOVED OR DIS-TURBED.

6.5 PUMP ASSEMBLY fig. 15Carry out component removal procedure as de-scribed in 6.4.The pump head can be replaced by disconnectingthe electrical connection at the pump and removingthe 4-Allen screws that secure the head to thepump base. Alternatively, the complete pumpassembly can be removed as follows:● disconnect the electrical connection from the

pump control box• locate and remove the pressure gauge securing

pin and disconnect the pressure gauge from thepump assembly

• Refer to fig. 15 and remove items A & B• Locate and remove the pump locking pin ‘G’ (it

may be necessary to remove the valve actuatorF to facilitate this) and lift the pump assemblyclear of the hydraulic manifold.

• Locate and remove the expansion pipe lockingpin, and disconnect the expansion pipe from thepump assembly

Replace in the reverse order.

6.6 AUTOMATIC AIR RELEASE VALVE fig. 15 (AAV)Carry out component removal procedure as de-scribed in 6.4.Locate and remove the pressure gauge pipesecuring pin and disconnect the pipe from thepump assembly. Locate and remove the AAVsecuring pin (G) and lift the AAV free from thepump assembly.Replace in the reverse order.

Fig. 15

AAV

A

B

G

F


6.7 SAFETY VALVE fig. 16

Carry out component removal procedure as de-scribed in 6.4.Disconnect and remove the safety valve outletpipe. Locate and remove the safety valve securingpin (B). The safety valve can now be removed.Replace in the reverse order.Check and clean (if necessary) the condense trap(see 6.29).

6.8 WATER PRESSURE SWITCH fig. 1Carry out component removal procedure as de-scribed in 6.4.Disconnect the 2-wires from the water pressureswitch, taking note of their locations. Locate andremove the pin that secures the water pressureswitch to the hydraulic assembly. Remove thewater pressure switch from the hydraulic assembly.Replace in the reverse order.

6.9 PRESSURE/TEMPERATURE GAUGE fig. 1Carry out component removal procedure as de-scribed in 6.4.Locate and remove the pressure gauge securingpin and disconnect the pressure gauge from thepump assembly. Locate the spring tabs on thepressure gauge body, push and hold tabs in, toenable extraction of the gauge from its location onthe control panel.Replace in the reverse order.

6.10 PRIMARY THERMISTOR fig. 17Carry out component removal procedure as de-scribed in 6.4.Unclip and remove the air chamber cover andremove the right side air baffle.Disconnect thermistor electrical plug.Using a 13mm spanner slacken and remove thethermistor and sealing washer (1,2) from the mainheat exchanger.NB, it may be necessary to disconnect or remove

the flow pipe from the heat exchanger to facilitatethis.Replace in the reverse order.

6.11 HIGH LIMIT THERMOSTAT fig. 18Carry out component removal procedure as de-scribed in 6.4.Unclip and remove the air chamber cover.

Pull off electrical connections from the high limitthermostat (2), slacken and remove retainingscrews (3).Replace in reverse order.

6.12 PRINTED CIRCUIT BOARD fig. 19Carry out component removal procedure as de-scribed in 6.4.Locate and remove the screws that secure thePCB cover, then remove cover. After carefullytaking note of all wiring connections, disconnectall wiring from the PCB, locate and remove thePCB securing screws (2,3,), remove the requiredPCB (Main or ignition control). Replace in thereverse order.

NOTEEnsure that any replacement PCB has the correctjumper tag configuration, and that the relevant gaspressures are correctly set/adjusted (see 7.8.1).

6.13 GAS VALVE fig. 20Carry out component removal procedure as de-scribed in 6.4. The gas valve must be changed ascomplete unit. Disconnect the electrical plug andleads from the gas valve.Slacken and unscrew gas valve inlet and outletconnections (3). Please note, the sealing wash-ers (2) must be discarded and replaced with newsealing washers (2). Locate and remove gas valveretaining screws on the underside of the boiler ifrequired. The gas valve can now be removed.Replace in the reverse order. Check and adjustburner pressure settings. WARNING, A GASSOUNDNESS CHECK MUST BE CARRIED OUT.

Fig. 18

Fig. 17

Fig. 16E

B


6.14 INTEGRAL TIME SWITCH (if fitted)Carry out component removal procedure as de-scribed in 6.4.Locate and remove the PCB cover and securingscrews (fig. 19/19A), locate and remove the timeclock retaining screws, remove time clock. Dis-connect wiring after carefully taking note of allelectrical connections. Replace in the reverseorder.

6.15 ELECTRODE, BURNER & INJECTORS fig. 21Carry out component removal procedure as de-scribed in 6.4.Unclip and remove the air chamber cover (2).Locate and remove the 6 screws securing thefront combustion cover (3), pull the cover towardsyou before lifting and disengaging. Disconnectthe electrode lead. Ease the electrode sealinggrommet from its seating (4).

FIG. 22: locate and remove the four screws whichsecure the burner in position (1), gently ease theburner out of its location. Once the burner hasbeen removed, the electrode retaining screw canbe removed. Locate the burner injectors (2) andremove (if necessary). Replace in the reverseorder. Please note, the injector sealing washers(3) must be replaced if the injectors have beenremoved, ensure all seals are in good condition,taking care to ensure they are replaced correctly.Replace in the reverse order.

6.16 FLUE FAN fig. 23Carry out component removal procedure as de-scribed in 6.4.Unclip and remove the air chamber cover, gently

Fig. 19a

M

M

CLK-1

CLK-4

Fig. 20

Fig. 21 Fig. 22


pull the cover towards you before lifting anddisengaging. Locate and remove the six screwsthat secure the front combustion cover, thenremove the cover. Disconnect the electrical con-nections and silicone tubes attached to the fan,noting their positions. Locate and remove thescrews (6) that secure the air pressure switchassembly (4 & 5). Locate and remove the screwsthat secure the flue hood and air baffle, disconnectthe flue clip (1) from the fan-flue elbow, and gentlyease the fan (3) & flue hood assembly (2) from itslocation. Locate and remove the four screws thatsecure the fan to the flue hood. Remove the fan toflue elbow. Replace in the reverse order. Ensure allseals are in good condition, taking care to ensurethey are replaced correctly.

6.17 MAIN HEAT EXCHANGER fig. 23/24Carry out component removal procedure as de-scribed in 6.4.Unclip and remove the air chamber cover, gentlypull the cover towards you before lifting anddisengaging. Locate and remove the six screws

that secure the front combustion cover, thenremove the cover. Remove the air chamber sidepanels if necessary by unscrewing the securingscrews. Disconnect the flow and return connec-tions (4,5, fig. 24) and the primary thermistor onthe heat exchanger. The heat exchanger can nowbe withdrawn from the appliance. Replace in thereverse order. Ensure all seals are in good condition,taking care to ensure they are replaced correctly.

6.18 AIR PRESSURE SWITCH fig. 23Carry out component removal procedure as de-scribed in 6.4.Unclip and remove the air chamber cover, gentlypull the cover towards you before lifting anddisengaging. Locate and remove the two screws(6) holding the air pressure switch to the airchamber. Disconnect the electrical connectionsand silicone tubes (10) attached to the air pressureswitch, noting their connections/positions. Replacein the reverse order. Ensure all seals are in goodcondition, taking care to ensure they are replacedcorrectly.

6.19 FLOW RESTRICTOR fig. 25Carry out the component removal procedure asdescribed in 6.4.Slacken the cold water outlet pipe (A) at the DHWflow switch and disconnect. Ease the flow restrictor(B) from its seating. Replace in the reverse order.Ensure all seals are in good condition, taking careto ensure they are replaced correctly.

6.20 DHW FLOW SWITCH fig. 25Carry out component removal procedure as de-scribed in 6.4.Disconnect the cold water inlet/outlet pipes (A)from the DHW flow switch. Disconnect the wiringto the DHW flow switch. Lift the DHW flow switchfrom its location. Replace in the reverse order.Ensure all seals are in good condition, taking careto ensure they are replaced correctly.

Fig. 25

�

��

�

�

�

�

�

�

A

B

C

Fig. 23

Fig. 24


6.21 DHW HEAT EXCHANGER fig. 16/16ACarry out component removal procedure asdescribed in 6.4.Before removing the DHW heat exchanger, it willbe necessary to remove the gas valve (see 6.13).Locate and remove the DHW outlet pipe (A) fromthe LH (left hand) DHW manifold and DHW outletconnection.Locate and remove the locking pins (1) that securethe flexible pipe (B) that connects both hydraulicmanifolds and then remove the pipe.Locate and remove the 2-screws (C) that securethe DHW heat exchanger to the LH and RH DHWmanifolds and gently ease the DHW heatexchanger from its location.Locate and remove the locking pin (2) that securesthe LH DHW manifold to the LH hydraulic manifoldand then remove the manifold.Gently ease the LH DHW manifold away from theLH hydraulic manifold and disconnect the wiringto the secondary (DHW) thermistor.Replace in the reverse order ensuring all sealsare correctly positioned and in good condition.Replace the gas valve in accordance with theinstructions detailed in 6.13.

6.22 VALVE ACTUATOR fig. 26Carry out component removal procedure as de-scribed in 6.4.Remove the locking pin (A) that secures theactuator (B) to the hydraulic manifold. Disconnectthe electrical plug from the actuator. Replace inthe reverse order.

6.23 DIVERTOR VALVE CARTRIDGE fig. 26Carry out component removal procedure as de-scribed in 6.4.Remove the valve actuator as described in 6.22.Remove the cartridge locking pin (C) and - using asuitable pair of pliers - withdraw the cartridgeassembly. The cartridge assembly is a non-serviceable item and therefore needs to be re-placed if it’s suspected as being damaged or worn.

Fig. 26

Fig. 26a

Replace in the reverse order ensuring that theseating cam inserts into the locating groovecorrectly (see fig. 26a). Ensure all seals are ingood condition, taking care to ensure they arereplaced correctly.

6.24 DHW THERMISTOR fig. 27Carry out component removal procedure as de-

scribed in 6.4.Disconnect the electrical plug. Using a suitablepair of pliers, remove the thermistor locking pin (E)and ease the thermistor (F) from its seating.Replace in the reverse order ensuring the sealingring is in good condition.

6.25 AUTO BY-PASS VALVE fig. 27Carry out component removal procedure as de-scribed in 6.4.Locate and remove the hydraulic cover locking pin(A) and remove the cover. Using a suitable hookedwire or screwdriver, gently ease the valve (C) fromits seating. Ensure all seals are in good condition,taking care to ensure they are replaced correctly.Replace in the reverse order ensuring the cartridgeis facing the correct way.

6.26 DHW NON-RETURN VALVE fig. 27Carry out component removal procedure as de-scribed in 6.4.Locate and remove the hydraulic cover locking pin(A) and remove the cover. Using a suitable hookedwire or screwdriver, gently ease the non-returnvalve (D) from its seating. Ensure all seals are ingood condition, taking care to ensure they arereplaced correctly. Replace in the reverse orderensuring the cartridge is facing the correct way.

6.27 EXPANSION VESSEL fig. 1Should the removal and replacement of the expan-sion vessel be deemed impractical, an externalexpansion vessel may be fitted to the return pipeas close to the appliance as possible.

6.27.1 EXPANSION VESSEL REMOVAL (with suffi-cient clearance above)Carry out component removal procedure as de-scribed in 6.4.Disconnect the flue from the appliance.Disconnect the flexible expansion pipe from thevessel. Locate and remove the four screws (A)that secure the vessel top holding plate (B),remove the plate (fig. 28). The expansion vessel

E

E

DC


can now be removed. Replace in the reverse order.Ensure all seals are in good condition, taking careto ensure they are replaced correctly.

6.27.2 EXPANSION VESSEL REMOVAL (with insuffi-cient clearance above)Carry out component removal procedure as de-scribed in 6.4.Disconnect the flexible expansion pipe from thevessel.

Disconnect the flue elbow or pipe from the appli-ance flue outlet. Unclip and remove the air cham-ber cover, gently pull the cover towards you beforelifting and disengaging. Remove the RH side panelof the air chamber. Disconnect the wiring to thefan, pressure switch, primary thermistor, overheatthermostat, condense switch & spark electrode,taking note of their locations. Carefully unclip thewires from the air chamber and withdraw the wiring& grommet from the air chamber.Disconnect the outlet gas pipe, the flow & returnpipes and the condense pipe from the air chamber.Locate and remove the 2-screws that secure thelower section of the air chamber. Locate andremove the 2-screws that secure the upper sec-tion of the air chamber. The complete air cham-ber assembly can now be lifted clear from theappliance.Locate and remove the 4-screws that secure thevessel (see fig. 28). The expansion vessel cannow be removed. Replace in the reverse order.Take extreme care when refitting the wiring to theair chamber. Ensure all seals are in good condi-tion, taking care to ensure they are replacedcorrectly.

6.28.1 LATENT HEAT COLLECTOR fig. 29/30Carry out component removal procedure as de-scribed in 6.4.Remove the flue hood and fan assembly asdetailed in 6.16. Disconnect and remove the inlet,outlet and condense pipes from the collector.Unscrew and remove the 3 screws that secure thecollector to the air chamber and disconnect thecollector from the flue connection. Replace in thereverse order ensuring all seals are intact andlocated correctly.

Fig. 28

B

A

6.28.2 DISMANTLING THE LATENT HEAT COLLEC-TORApart from routine cleaning of the coil, the latentheat collector is a non-serviceable component,therefore, there is no requirement to disassemblethe collector.

6.29 CONDENSE TRAP REMOVAL fig. 31Carry out component removal procedure as de-scribed in 6.4.Disconnect the flexible condense pipe (1) from thecondense trap. Locate and remove the condensepipe locking pin and disconnect the condense pipe(2) from the condense trap. Locate and disconnectthe condense pressure switch pipe from the con-dense trap (3). Carefully remove the condensetrap. Replace in the reverse order.

Fig. 29

Fig. 30

Fig. 31


SECTION 7 CHECKS, ADJUSTMENTS AND FAULT FINDING

7.1 CHECKING APPLIANCE OPERATIONWhen carrying out any repairs or servicing to theappliance, the relevant commissioning proce-dure must be undertaken to ensure the continuedsafe operation of the appliance. Particular atten-tion should be made to ensure gas soundness,water soundness and the electrical integrity of theappliance.

7.2 APPLIANCE MODE OF OPERATIONNOTEThere must be sufficient system water pressure(min. 0.5 bar) to ensure the water pressure switchis activated. If there is insufficient system pres-sure the pump and fan will be prevented fromoperating.

7.2.1 SELECTOR SWITCH IN THE OFF POSITIONWhen the selector switch is in the OFF position,the Green LED status indicator will flash every 6-seconds to confirm the appliance is in standbymode. The divertor valve is in the DHW position.The appliance will not respond to any DHW orheating requests.

Active functions:●●●●● frost-protection system●●●●● pump anti-block●●●●● valve actuator anti-block● fan over-run.

7.2.2 SELECTOR SWITCH IN THE HOT WATERONLY POSITIONWhen the selector switch is in the HW onlyposition, the Green LED is illuminated:●●●●● flashing every 6-seconds if no DHW request is

active●●●●● constant during a DHW request.

The divertor valve is in the DHW position. Theappliance will respond to any DHW requests.

Active functions:●●●●● frost-protection system●●●●● pump anti-block●●●●● valve actuator anti-block●●●●● fan over-run.

7.2.3 SELECTOR SWITCH IN THE HEATING & HOTWATER POSITIONWhen the selector switch is in the heating & HWposition, the Green LED is illuminated:●●●●● flashing every 6-seconds if no Heat or DHW

request is active●●●●● constant during a heat or DHW request.

The divertor valve remains in the DHW position ifno heat request is active. The appliance willrespond to any heating or DHW requests.

Active functions:●●●●● frost-protection system●●●●● pump anti-block●●●●● valve actuator anti-block●●●●● fan/pump over-run.

7.2.4 APPLIANCE FUNCTIONS●●●●● Frost-protection: this function is only active

when there are no requests for heating or HW.When the temperature of the primary thermis-tor drops below 5 °C, the valve actuator willmotor to the heating position, whereupon theboiler will operate on minimum power until thetemperature of the primary thermistor reaches35 °C. Thereafter the pump will over-run for 30-seconds.

●●●●● Anti-block cycle: when there has been noheating or HW request for 19-hours, the anti-block cycle is activated. The valve actuator willmotor from the DHW position to the heatingposition and then motor back to the DHWposition. Thereafter the pump will be activatedfor a period of 30-seconds.

●●●●● Fan over-run: should the temperature of theprimary thermistor exceed 78 °C after a heatingor DHW request, the pump and/or fan will runfor a period of 30-seconds.

●●●●● AUTO function: the AUTO function permits theboiler (when the set-point is within the AUTOrange) to automatically adjust (raise) the heatingflow outlet temperature should the room thermo-stat contacts remain closed for more that 20-minutes.

7.2.5 DHW MODE fig. 32With the selector switch in the Heating & HWposition, or HW only position and a DHW outlet isopened, the appliance will operate in the HWmode. The valve actuator will motor to the HWposition (if a heating request was active) and thepump and fan will be active. The operation of thefan causes the air pressure switch (APS) to delivera signal voltage to the control PCB. A slow ignitionsequence is enabled, whereby the current sup-plied to the gas valve modulating coil is progres-sively increased from minimum to maximum overa period of 8-seconds. During this period theignition electrode sparks continuously even if theburner has ignited.


NOTEIf the spark/sensing electrode does not senseignition the appliance will then go to lockout.Ignition is sensed by the electronic circuitry toensure flame stability at the burner. Once suc-cessful ignition has been achieved, the electroniccircuitry modulates the appliance output in order toachieve the DHW set-point (the position of theDHW temperature selector) as measured at thesecondary thermistor.When the set-point has been reached, the appli-ance will begin the modulation phase whereby thefan and gas valve will continuously modulate tomaintain the set-point.If the temperature continues to rise and exceedsthe set-point by 5 °C, the burner will shut down untilthe temperature drops to set-point + 4 °C, wherebya new ignition sequence will be enabled.When the request for DHW has been satisfied, theappliance fan may continue to operate to dissipateany residual heat from within the appliance.

7.2.5.1 DHW PARAMETERS

7.2.6 HEATING MODE fig. 33With the selector switch in the Heating & HWposition and the relevant controls (time clock,room thermostat, etc,) are calling for heat, theappliance will operate in the heating mode. Thevalve actuator will motor to the heating positionand the pump and fan will be active. The operation

of the fan causes the air pressure switch (APS) todeliver a signal voltage to the control PCB. A slowignition sequence is enabled, whereby the currentsupplied to the gas valve modulating coil is pro-gressively increased from minimum to maximumover a period of 8-seconds. During this period theignition electrode sparks continuously even if theburner has ignited.

NOTEIf the spark/sensing electrode does not senseignition the appliance will then go to lockout.Ignition is sensed by the electronic circuitry toensure flame stability at the burner. Once suc-cessful ignition has been achieved, the electroniccircuitry allows 75% of the full gas rate through theappliance. After 15 minutes the gas rate is increasedto maximum (100%).When the set-point has been reached (the positionof the heating temperature selector) as measuredat the primary thermistor, the appliance will beginthe modulation phase whereby the fan and gasvalve will continuously modulate to maintain theset-point.If the temperature continues to rise and exceedsthe set-point by 6 °C, the burner will shut down andthe boiler will perform a three-minute anti-cycle(timer delay).A new ignition sequence will be enabled when the3-minute anti-cycle has been performed and thetemperature at the primary thermistor has dropped6 °C below the set-point.

NOTESThe timer delay can be de-activated by the inser-tion of a ‘jumper’ on the PCB at JP1 or by isolatingthe appliance from the electrical supply for 30seconds.Any DHW requests will always have priority overa heating request.When the request for heating has been satisfied,the appliance pump and fan may continue tocirculate to dissipate any residual heat within theappliance.

Fig. 32

RANGE MINIMUM MAXIMUMTemperature (°C) 37.5 60DHW NTC fault ON at 50 °C OFF at 55 °C

Fig. 33


7.2.6.1 HEATING PARAMETERS

When the boiler is operating in the AUTO range,the Green LED flashes rapidly to signify the AUTOfunction is active.

AUTO FUNCTIONWhen the heating temperature selector is setwithin the AUTO range (AUTO sector) the boilerwill automatically raise the heating flow outlettemperature by 5 °C every 20-minutes that theroom thermostat contacts remain in the closedposition or until the boiler reaches the maximumoperating temperature.

7.3 CHECKING AND ADJUSTING BURNER PRES-SURE (see fig. 15)Although the burner pressure is factory set, it isnecessary to check it during servicing or if the gasvalve has been removed.Isolate the appliance from the electrical supplyand attach a suitable manometer to the gas valveoutlet test nipple.

RANGE MINIMUM MAXIMUMTemperature (°C) 40 801ST sector 40 55AUTO sector 55 652ND sector 65 80

Fig. 34

7.3.1 SETTING THE MAXIMUM BURNER PRESSUREfig. 39Light the boiler as described in 5.7 and comparethe reading on the manometer with the valuedescribed in 2.3. If adjustment is required, re-move the protective cap from the gas valvemodulating coil assembly and turn the outer(10mm) nut clockwise to increase, or counter-clockwise to decrease the burner pressure.NOTEAlways check and/or adjust the minimum andmaximum gas pressures whilst the appliance is inthe HW only mode. Ensure a DHW outlet (pref-erably the bath) is fully open, and that the HWtemperature selector is at maximum.

7.3.2 SETTING THE MIMIMUM BURNER PRES-SURE fig. 34Once the maximum burner pressure has beenchecked and/or adjusted, remove one of the greywires from the modulating coil. Compare thereading on the manometer with the value de-scribed in 2.3. If adjustment is required, turn theinner (red) crosshead screw clockwise to in-crease, or counter-clockwise to decrease theburner pressure, whilst ensuring that the outer(10mm) nut does not move. When checking and/or adjustment has been completed, isolate theappliance from the electrical supply, replace theprotective cap, refit the grey wire to the modulat-ing coil, remove the manometer and tighten theoutlet test nipple.IMPORTANT, A GAS SOUNDNESS CHECKMUST BE CARRIED OUT.

7.3.3 SETTING THE MINIMUM CENTRAL HEATINGOUTPUTTHIS CAN ONLY BE CARRIED OUT AFTERTHE MAXIMUM AND MINIMUM GAS PRES-SURES HAVE BEEN SET.● Isolate the appliance from the electrical supply.● Attach a manometer to the gas valve outlet test

nipple.● Insert a jumper tag at JP2.● Switch the appliance ON in the heating mode.● Turn potentiometer P5 to the minimum position● Adjust potentiometer P4 to the required value

shown in section2.3 (section 10.2 for LPG), i.e.minimum burner pressure (central heating).

● Turn potentiometer P5 back to the maximumposition.

● Isolate the appliance from the electrical supply.● Remove the manometer, tighten the outlet test

nipple, and check for soundness.

7.4 COMBUSTION ANALYSIS TESTA combustion analysis check (see 2.12 Nat. Gasor 10.2 LPG) can easily be carried out on theappliance via the test points located on the top ofthe appliance, however you must check that theburner pressures are set correctly (see 7.3).● Isolate the appliance from the electrical supply

and turn the mode selector switch to the OFF/RESET position.

● Locate and remove the CO test point sealingscrew (see fig. 36).

● Insert the flue gas analyser probe into the testpoint.

● Restore the electrical supply to the appliance● Remove the mode selector knob and turn the

shaft fully clockwise (see fig. 37).Fig. 35

��

��

��

� ��

��

�

��


● The boiler will now enter the combustion analy-sis mode (CO mode) for a period of 15 minutes,signified by the LED flashing Yellow. Duringthis time, the boiler will remain on full gas.

● Once the flue gas analysis has been made, turnthe shaft back to the required position andreplace the mode selector knob.

● Remove the probe and replace the sealing screw.

7.5 CHECKING THE EXPANSION VESSELCarry out the component removal procedure asdescribed in 6.4. You must ensure that the boileris completely drained of water.Using a suitable pressure gauge, remove dustcap on expansion vessel and check the chargepressure. The correct charge pressure should be1.0 bar ± 0.1 bar.If the charge pressure is less, use a suitablepump to increase the charge.

NOTEYou must ensure the drain valve is in the openposition whilst re-charging takes place. Replacethe dust cap and carry out the relevant commis-sioning procedure (section 5).

7.6 EXTERNAL FAULTSBefore carrying out any faultfinding or componentreplacement, ensure the fault is not attributable toany aspect of the installation.

7.6.1 INSTALLATION FAULTS7.7 ELECTRICAL CHECKS

Any electrical checks must be carried out by asuitably qualified person.

7.7.1 EARTH CONTINUITY TESTIsolate the appliance from the electrical supply,and using a suitable multi-meter carry out aresistance test. Connect test leads between anappliance earth point and the earth wire of theappliance supply cable. The resistance should beless than 1 OHM. If the resistance is greater than1 OHM check all earth wires and connectors forcontinuity and integrity.

7.7.2 SHORT CIRCUIT CHECKIsolate the appliance from the electrical supply,and using a suitable multi-meter, carry out a shortcircuit test between the Live & Neutral connec-tions at the appliance terminal strip (fig.12).Repeat above test on the Live & Earth connec-tions at the appliance terminal strip (fig.12).NOTEShould it be found that the fuse has failed but nofault is indicated, a detailed continuity. Check willbe required to trace the fault. A visual inspectionof components may also assist in locating thefault.

7.7.3 POLARITY CHECKWith the appliance connected to the electricalsupply and using a suitable multimeter, carry outthe following voltage tests:●●●●● Connect test leads between the Live & Neutral

connections at the appliance terminal strip(fig.12). The meter should read approximately230V ac. If so proceed to next stage. If not, see7.7.4.

●●●●● Connect test leads between the Live & Earthconnections at the appliance terminal strip(fig.12). The meter should read approximately230V ac. If so proceed to next stage. If not, see7.7.4.

●●●●● Connect test leads between the Neutral &Earth connections at the appliance terminal strip(fig.12). The meter should read approximately 0- 15Vac. If so polarity is correct. If not, see 7.7.4.

Fig. 37

Symptom Possible causesNo ignition Check wiring

Check electrical supplyNo hot water Check hot/cold pipe

work is not reversedNo central heating Check wiring of room thermostat

and/or other external controls

Frequency Faults/StatusON every 0.5-secs Final fault, e.g.:

●●●●● water pressure switch●●●●● condense pressure switch

●●●●● fan/flue problem●●●●● limit thermostat

Solid ●●●●● primary NTC open/short circuit

RED LED

Fig. 36

Air analysisoutlet

Fumes analysisoutlet Frequency Faults/Status

ON every 0.5-secs CO function activeSolid DHW thermistor fault (see 7.2.5.2)

YELLOW LED

Frequency Faults/StatusON every 6-secs At stand-by with no faults

Flashing 8-times a second AUTO function activeON every 0.5-secs Temporary fault, e.g.:

●●●●● APS fault●●●●● low water pressure

Solid Active for heat/DHW request

GREEN LED

Rotate shaft fullyclock wise


7.7.4 REVERSED POLARITY OR SUPPLY FAULTRepeat the above tests at the appliance isolator,if testing reveals correct polarity and/or supply atthe isolator, re-check wiring and connections be-tween the isolator and the appliance.If tests on the isolator also reveal reversed polar-ity or a supply fault, consult the local electricitysupplier for advice.

7.7.5 RESISTANCE TO EARTH CHECKIsolate the appliance from the electrical supplyand using a suitable multi-meter carry out aresistance test. Connect test leads between theLive & Earth connections at the appliance termi-nal strip (fig.12). If the meter reads other thaninfinity there is a fault that must be isolated, carryout a detailed continuity check to identify thelocation of the fault.

IMPORTANTThese series of checks must be carried outbefore attempting any faultfinding procedures onthe appliance. On completion of any task thatrequired the disconnection and re-connection ofany electrical wiring or component, these checksmust be repeated.

7.8 FAULT FINDINGBefore attempting any faultfinding, the electricalchecks as detailed in 7.7 must be carried out.Isolate the appliance from the electrical supply.Disconnect any external controls such as roomthermostats etc. from the boiler.

7.8.1 REPLACING THE MAIN PCBWhen replacing the main PCB it’s essential thatthe potentiometers are set as follows:● It’s essential that the minimum - central heating

- gas pressure is checked/adjusted as de-scribed in 7.3.3

● P4 - to be used to set/adjust the minimumheating output

● P5 - set at maximum.

EFFECT OF JUMPER TAGS (part code 7232)FITTED TO THE MAIN PCB AT:● JP1 - disables DHW function● JP2 - cancels anti-cycle function and initial

heating output (75% of maximum at start up)● JP3 - for LPG boilers only● JP4 - enables DHW temperature stabiliser

function (boiler modulates at set point andremains on minimum power, even if the setpoint is exceeded).

Restore the electrical supply to the boiler andturn the selector switch to the on position. Theboiler should now function as described in sec-tion 7.2. Should the boiler fail to respond, the in-ternal fuses and connectors should be checkedto ensure integrity and continuity. If the boiler stillfails to respond, refer to the detailed faultfindingflowcharts overleaf.

7.9 FAULT CODESWhen the boiler is in a fault condition, the LED isdisplayed in a colour and/or frequency that isrelevant to the fault. To reset the boiler, turn the

Frequency Faults/StatusON every 0.5-secs CO function active

Solid DHW* thermistor fault (see 7.2.5.2)

YELLOW LED

* When there is a fault condition with the DHW thermistor, theappliance will still operate and produce limited hot water. ThePrimary thermistor will control the temperature of the DHWduring this period and the outlet temperature is fixed at 50-55oC.

mode selector switch to the reset position (0) for2-minutes’ then back to the relevant mode ofoperation.If the boiler does not reset, refer to the followingsection and the detailed faultfinding flowchartsoverleaf.

Frequency Faults/StatusON every 0.5-secs Final fault, e.g.:

●●●●● water pressure switch●●●●● condense pressure switch

●●●●● fan/flue problem●●●●● limit thermostat

Solid ●●●●● primary NTC open/short circuit

RED LED


7.10.1 FAULT FINDING TEST ‘A’: CHECKING OPERATION OF ELECTRONIC CONTROL BOARD ATSTART UP

MAINS ON FAN

REPLACE FAN

YES

NO

YES

REPLACE WIRINGOR CONNECTIONS

MAINS ON PUMP

REPLACEPUMP

NO

YES

YES

YESNO

NO

A1

A

CHECK &/ORREPLACE WIRING

ANDCONNECTIONS

MAINS ON FAN

CONNECTOR CN4.1 & CN4.2

ON PCB

MAINS ON PUMP CONNECTOR

CN2.1 & CN2.2ON PCB FAN RUNNING

PUMP RUNNING

GREEN LEDBLINKS

START

NO

NO

YES

REPLACE WIRINGOR CONNECTIONS

AIR FLOW SWITCH

OFF?

REPLACE AIRFLOW SWITCH ORCHECK FLUE GAS

TUBE

YES

REPLACECONTROL BOARD

ISTHERE 0 VCC

BETWEEN TERMINALS CN8.3 & CN8.5

ON PCB

NO

NO

YES

MADE A LINK BETWEEN BLACK &BLACK WIRES AT BOILER

TERMINAL STRIP AND CLOSE THETIMER CONTACT

SWITCH ON BOILER ANDSELECT MODE TO

WINTER C/HTHERMOSTAT AT MAX.

YES

LOOSE THE PUMPACTING WITH A

SCREWDRIVER ONTHE IMPELLER

RESTART THETEST

NO

NO

NO

NO

IS ROOM THERMOSTATINPUT LINKED

MADE A LINKBETWEEN THE ROOMTHERMOSTAT INPUT

CHECK IDRAULICCIRCUIT

WATERPRESSURE SWITCH

IS OK

NO

ISTHERE 24dc


ON PCB


YESIS

THERE 24dc BETWEEN TERMINALS

CN9.1 & CN9.2 ON PCB

CHECK WIRING ANDCONNECTIONS ORWATER PRESSURE

SWITCH

MAINSBETWEEN PIN CN1.4 & CN1.5

ON PCB


RESTART THETEST

CHECK WIRING ORCONNECTIONS

BETWEEN TERMINALSTRIP AND CONTROL

BOARD

YES

YES

YES

YES

NO

NO

PUMP RUNNING

YES


7.10.2 FAULT FINDING TEST ‘A’

YES

NO

NO MAINS ON E.V.G.

NO

YES

NO

NO

YES

YES

YES

NO

IS THERE 24 Vdc

BETWEEN TERMINALSCN8.4 & CN8.5

ON PCB

A

REPLACESENSING/SPARKELECTRODE AND

LEADREPLACE PCB

SENSINGSPARK ELECTRODE

AND LEAD OK

CHEKSENSING/SPARKELECTRODE AND

LEAD

END

LOCKOUT

IGNITION

REPLACE EVGCHECK GAS

EVG OK

IGNITION

SPARK ATELECTRODE

CHECK WIRING ANDCONNECTIONS OR

HIGH LIMIT THERMOSTAT

CHECKSENSING/SPARKELECTRODE AND

LEAD

ISTHERE 230 Vac


ON PCB

ISTHERE 0 Vdc


ON PCB

NO

YES

NO

CHECK WIRINGAND

CONNECTIONS

NO

DO THEAIR FLOW SWTCH

TURN ON

CHECK WIRING ANDCONNECTIONS, AIR FLOW

SWITCH AND CONTROLBOARD

YES

NO

ARE THEVENTURI TUBE

AND THE SILICONE AIR TUBES

CLEANCHECK/CLEAN THEVENTURI TUBE AND

SILICONE AIRTUBES

ISTHE AIR DP >11 mmCH2O

CHECK THE FANAND/OR FLUE GAS

TUBE

CHECK REPLACEAIR FLOW SWITCH

NO

YES

YES

REPLACE THECONTROL BOARD

YES

NO

NO

IS THERE 230 Vac


ON PCB

CHECK AND/ORREPLACE PCB

IS THERE 24 Vdc


ON PCB

CHECK AND/ORREPLACE PCB

IS THERE 24 Vdc


ON PCB

NO


HIGH LIMITTHERMOSTAT

NO

YES

YES

YES

AFTER


7.10.3 FAULT FINDING TEST ‘A1’

NO

YES

A1


FUSE OK

CHECK FUSE F1ON CONTROL

BOARD

RED LEDBLINKS

MAINS PRESENT BETWEEN

TERMINALS CN1.2&CN1.3 M2.2 ON

CONTROL

YES

NO

RESTART THETEST

REPLACE FUSE

NO

NO

REPLACE CONTROLBOARD

RED LEDLIGHT

YES

YES

SWITCH ON/OFFSELECTOR ON OFF

POSITION

SWITCH ON/OFFSELECTOR TO

WINTER POSITION

GREEN LEDBLINKS

RESTART THETEST

YES

YES

NO

CHECK CH NTCSENSOR OR WIRINGAND CONNECTIONS

YELLOW LEDLIGHT

NO

CHECK WIRING ANDCONNECTIONS, WATERPRESSURE SWITCH AND

HYDRAULIC CIRCUIT

NO

RECHECK SUPPLYFUSE &

CONNECTORS TOBOILER

TERMINALS

MAINS PRESENT BETWEEN

BLUE & BROWN WIRES ATBOILER TERMINAL

STRIP

NO

REPLACE WIRING ORCONNECTIONS

TERMINAL STRIP ANDCONTROL BOARD

YES

YELLOW LEDBLINKS

CHIMNEYSWEEPER CYCLE.

RESET ANDRESTART TEST

NO

ISTHERE 0 VCC


ON PCB

ISTHERE 24 Vdc


ON PCBIS

THERE 24 Vdc BETWEEN TERMINALS




HIGH LIMIT THERMOSTAT

ISTHERE 24 Vdc


ON PCB


ISTHERE 24 Vdc


ON PCB


AIR PRESSURE SWITCHREPLACE

CONTROL BOARD

YES

YES

YES

YES

YES

NO

NO

NO

NO

YES

BOARD


7.10.4 FAULT FINDING TEST ‘B2’: CHECK CONTROL IN DHW MODE

NO

NO

NO

NO

NO

YES

YES

YES

ISVOLTAGE

ACROSS TERMINALSOF MODULATOR

COIL >10 VDC

REPLACE WIREAND

CONNECTIONS


REPLACEMODULATOR COIL

IS THE RESISTENCE OF

MODULATOR COIL ABOUT 70/80

OHM

ISTHERE A

VOLTAGE >10 VDCBETWEEN TERMINALS


DOES BURNER LIGHT

CHECK BOILERSTARTUP: TEST A

TURN ON TAP

SWITCH ON BOILER ANDSELECT MODE TO

SUMMER. DHWTHERMOSTAT AT MAX.

START

YES

SWITCH DHWTHERMOSTAT AT MIN.

DO BURNER AND FAN

SWITCH OFF

IS

TEMPERATURE >40 ûC

WAIT D.H.W.TEMPERATURE

>40 ûC


YES

NO

YES

NO

ISTHERE 24 Vdc


ON PCB

REPLACECONTROL

BOARD

YES


DHW SWITCH

YES

NO

ISTHERE 0 Vdc


ON PCB

NO

WAIT TILL THEVOLTAGE BETWEEN

TERMINAL CN9.3 & CN9.4 ON PCB IS < 1.2 Vdc

IS THEVOLTAGE BETWEENTERMINAL CN9.3 &CN9.4 ON PCB IS

< 1.2 VdcIS

TEMPERATURE >60 ûC


>60 ûC

YES

YES

NO

ISD.H.W. NTC

OK

REPLACE D.H.W. NTC


YES

B

NO

D.H.W.

D.H.W.


7.10.5 FAULT FINDING TEST ‘C’: CHECK CONTROL IN C/H MODE

NO

YES

NO

YES YES

NO

YES NO



REMOVE JUMPER

IS TIMER JUMPER

ON

ISVOLTAGE

ACROSS TERMINALS OFMODULATOR COIL

>10 VDC

ISVOLTAGE


< 8 VDC

CHECK BOILERSTARTUP TEST A

SET TIMERJUMPER ON

DOES BURNER

LIGHT

MADE A LINK BETWEENBLACK & BLACK WIRES AT

BOILER TERMINALSTRIP AND CLOSE THE

TIMER CONTACT

SWITCH ON BOILERAND SELECT MODE

TO WINTER C/HTHERMOSTAT AT

MAX.

START

RESTART THETEST

NO

NO

YES

REPLACE WIREAND

CONNECTIONS


REPLACEMODULATOR COIL

IS THE RESISTENCE OF

MODULATOR COILABOUT 70/80

OHM

ISTHERE A

VOLTAGE <8 VDCBETWEEN TERMINALS


YESC

ISVOLTAGE


>10 VDC

SWITCH CHTHERMOSTAT AT MIN.

NO

YES

NO

WAIT TILL THEVOLTAGE BETWEEN

TERMINAL CN9.3 & CN9.4 ON PCB IS < 1.2 Vdc

IS THEVOLTAGE BETWEENTERMINAL CN9.3 &CN9.4 ON PCB IS

< 1.2 Vdc

IS

TEMPERATURE >80 ûC


>80 ûC

YES

NO

YES

NO ISC.H. NTC

OK

REPLACE C.H. NTC


YES

D.H.W.


7.10.6 TEST ‘C’ CONT’D

YES

WAIT 3 MIN.

C

NO

DO BURNER AND FAN

SWITCH OFF

ISWATER FLOWTEMPERATURE

>40 ûC

WAIT WATER FLOWTEMPERATURE

>40 ûC


SWITCH CHTHERMOSTAT AT MAX.

DO BURNER AND FAN

SWITCH ON

ISWATER FLOWTEMPERATURE

>80 ûC

WAIT WATER FLOWTEMPERATURE

< 80 ûC

NO YES


REMOVE JUMPER

IS TIMER JUMPER

ON

RESTART THETEST

DO BURNER AND FAN

SWITCH ON

OPEN THE TIMERCONTACT


DO BURNER

AND FAN SWITCH

OFF

DOPUMP SWITCH

OFF

END


YES

YES

YES

NO

NO

NO

NO

NO

NO

YES

YES

YES

WAIT30 SECS.

NO

ISC.H. NTC

OK

REPLACE C.H. NTC


YES


SECTION 8 WIRING DIAGRAMS

8.1 EXTERNAL WIRINGThe appliance comes with a factory fitted clock toallow basic operation of the boiler (fig. 38). Ifexternal controls are to be added to the system,they must be connected to the appliance asshown in the following diagrams. For advice oncontrols that are not featured in this book, pleasecontact the Service & Technical Helpline on0870-264-1220.

8.2 TYPICAL CONTROL APPLICATIONSThe appliance can be used with the followingcontrols:● external single-channel, voltage-free time clocks● programmable room thermostats.

In addition, the appliance can be used in con-junction with a typical ‘S’-Plan system, pleasecontact the technical help line (0870 264 1220)for further detailed instruction.

NOTEThis appliance is not suitable for use with ‘Y’-Plansystems.

Fig. 38

8.3 ROOM THERMOSTATShould a room thermostat be required, it must beof the ‘voltage-free’ type, and should be con-nected to the appliance as shown in fig. 39.

8.4 OTHER CONTROLSContact the controls manufacturer and/or thetechnical help line should you require more spe-cific information on the suitability of a particularcontrol.Further guidance on the recommended practicefor the installation of external controls, can befound in CHeSS - HC5/HC6 (www.energy-efficiency.gov.uk).

Fig. 39

factory configuration


FUNCTIONAL DIAGRAM

NOTE: L-N-E CONNECTION IS ADVISABLE

Fig. 40

Key

D.H

.W.F

.S.

Dom

estic

hot

wat

er f

low

sw

itch

P.S

.P

ress

ure

switc

hP

.D.S

.D

iffer

entia

l pre

ssur

e sw

itch

H.L

.T.

Hig

h lim

it th

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osta

tH

.T.

Hea

t the

rmis

tor

D.H

.W.T

.D

omes

tic h

ot w

ater

ther

mis

tor

C.P

.S.

Con

dens

e pr

essu

re s

witc

hM

OD

Mod

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orF

Fan

PP

ump

3 W

3 w

ay m

otor

OP

EG

as v

alve

sol

enoi

dsJP

1C

.H. o

nly

sele

ctor

JP2

Set

ting

timer

JP3

Nat

ural

gas

or L

.P.G

. sel

ecto

r

JP4

Jum

per

disa

ble/

enab

le D

HW

abs

olut

the

rmos

tat

P1

Dom

estic

hot

wat

er te

mpe

ratu

re c

ontr

olP

2C

entr

al h

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mpe

ratu

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olP

3O

ff/su

mm

er/w

inte

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mbu

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inim

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g re

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tion

P5

Hea

ting

pote

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met

er (m

ust

be s

et to

max

)F

1-F

2F

use

2 A

FS

.S.E

.S

park

\Sen

se e

lect

rode

CP

04X

Con

trol

boa

rdC

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CN

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onne

ctor

sR

L1

Pum

p re

lay

RL

2F

an re

lay

RL

3D

iver

ter v

alve

mot

or re

lay

RL

4Ig

nitio

n re

lay

TR

F1

Tra

sfor

mer

TR

XIg

nitio

n tr

asfo

rmer

AC

F01

XIg

nitio

n co

ntro

l boa

rdM

3-M

6E

xter

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onne

ctio

ns b

lock

LE

DLe

d O

K (g

reen

)Le

d al

arm

(red

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ombu

stio

n te

st (b

link

oran

ge)

F2

= fu

se 2

AF


SECTION 10 L.P.G. INSTRUCTIONS

10.3 CONVERTING THE APPLIANCE GAS TYPETo convert the appliance to another gas type it isnecessary to change the burner injectors andadjust the gas pressures. It is also necessary toensure the jumper tag at JP3 is enabled or disa-bled according to the gas type used.● To change the injectors see section 6.● For correct jumper tag configuration see 7.8.● Ensure you have the correct gas conversion

kit, part code: 01005407

10.4 GAS SUPPLYThe gas supply must be connected to the appli-ance by a competent LPG installer and must beof sufficient size to supply the appliance at itsmaximum output.An existing supply must be checked to ensurethat it is of adequate size to deal with the maxi-mum rated input of this and any other appliancesthat it serves.

10.5 GAS SUPPLY INSTALLATIONThe entire installation including the meter mustbe purged and checked for gas soundness.

10.6 CHECKING AND ADJUSTING BURNER PRES-SURE (see fig. 22)Isolate the appliance from the electrical supplyand attach a suitable manometer to the gas valveoutlet test point.

10.6.1 SETTING THE MAXIMUM BURNER PRES-SURE fig. 35Light the boiler as described in 5.7, fully open aDHW outlet (preferably the bath) and ensure theHW temperature selector is set at maximum.Allow the appliance to stabilise.Compare the reading on the manometer with thevalue described in 10.2. If adjustment is required,

BS 6798 INSTALLATION OF BOILERS OF RATED NOT EXCEEDING 60kW

BS 5449 PART 1 FORCED CIRCULATION HOT WATER SYSTEMS

BS 5546 INSTALLATION OF GAS HOT WATER SUPPLIES FOR DOMESTIC PURPOSES

BS 5440 PART 1 FLUES

BS 5482 PART 1 DOMESTIC BUTANE & PROPANE GAS BURNERS IN PERMAMENT DWELLINGS

10.1 RELATED DOCUMENTS

10.2 TECHNICAL DATAGAS PRESSURES 85 HE 100 HE

Inlet pressure 37 mbar 37 mbar

Burner pressure maximum 35.70 mbar 35.50 mbar

Burner pressure minimum (heating) 12.80 mbar 10.00 mbar

Burner pressure minimum (DHW) 4.90 mbar 4.50 mbar

Maximum gas rate 1.94 Kg/h 2.25 Kg/h

Minimum gas rate 1.16 Kg/h 1.16 Kg/h

Injectot size (quantity) 12 x 0.76 14 x 0.76

SEDBUK (%) 87.7 Band “B” 87.9 Band “B”

NOx (max - min) PPM 200 - 120 250 - 180

CO (max - min) PPM 90 - 100 100 - 190

CO2 (%) 7.60 - 4.35 8.20 - 4.00

CO/CO2 ratio (max - min) 0.001 to 1 - 0.002 to 1 0.001 to 1 - 0.005 to 1

remove the protective cap from the gas valvemodulating coil assembly and turn the outer (10mm)nut clockwise to increase, or counter-clockwise todecrease the burner pressure.

10.6.2 SETTING THE MINIMUM BURNER PRESSUREfig. 34Once the maximum burner pressure has beenchecked and/or adjusted, remove one of the greywires from the modulating coil. Compare thereading on the manometer with the value de-scribed in 10.2.If adjustment is required, turn the inner (red)crosshead screw clockwise to increase, or coun-ter-clockwise to decrease the burner pressure,whilst ensuring that the outer (10mm) nut doesnot move. When checking and/or adjustmentand/or adjustment has been completed, isolatethe appliance from the electrical supply, close theDHW outlet, replace the protective cap, refit thegrey wire to the modulating coil, remove themanometer, and tighten the outlet test point.

IMPORTANT, A GAS SOUNDNESS CHECKMUST BE CARRIED OUT.


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COLLECTIVE MARK

Heating Services provides after-sales assistance and Technical advice forProcombi HE Boilers

Service & Technical Helpline: 0870-264-1220Heating Services, PO BOX 167, BRADFORD, BD19 4WL.

We reserve the right to change the specifications without prior notice. Consumers’ statutory rights are not affected

installation & servicing instructions - heating spares ltd

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