operating, installation and maintenance manual for ct … · eco calorifier, its installation,...

By Appointment toHer Majesty the Queen

Boiler Manufacturers & EngineersHoval Ltd Newark

Date: March 2018

Ref: 4214941-02

Operating, Installation and Maintenance Manual for CT-plus eco Calorifiers

2 Table of Contents

3

4

5-6

7-8

9-13

14

15

16

17

18

19

20

21

Introduction

Description of CT-plus eco Calorifier

Technical and Performance Details CT-plus eco Calorifier

Installation and Piping Layouts

Unvented Systems

Commissioning & Operation

Inspection and Maintenance

Immersion heaters

Immersion heater wiring diagram

Fault Finding Chart

Wiring Diagrams for Open Vented Calorifiers

Wiring Diagrams for Unvented Calorifiers

Notes

egaPstnetnoC

These instructuctions should be read and understood before attempting to install,commission or operate this unit.

Material in this publication may not be reproduced without Hoval’s written permission.

Hoval reserve the right to change specifications without notice.

4214941-02March 2018

3Introduction

The installation should be in accordance withcurrent I.E.E. regulations, relevant British Stan-dard and Codes of Practice, Building Regula-tions and Local Authority Bylaws.

Commissioning should be arranged via theheating engineer. Hoval engineers are availableto carry out this work if requested. Where thecalorifier installation is part of a Hoval boilerpackage it will normally be commissioned atthe same time and entry made on the reportopposite.

Commissioning/Combustion Report

A note should be entered below by the person responsible for the plant, giving the boiler, calorifiermodel and its output and serial number, as indicated on the nameplate.

Calorifier Model:

Boiler type / Model:

Date of installation:

Output l/hr:

Serial Number:

4214941-02March 2018

Introduction

These instructions have been written to give a brief description of the CT-plus eco Calorifier, its installation, commissioning, operation and subsequent maintenance.

The installation of calorifiers and their ancillary equipment is normally carried out by an heating engineer. For the purpose of this manual he is regarded as the installer, and, as such, it is his responsibility to ensure that he has read and understood the contents of this manual before installing the calorifier.

It is essential that each calorifier has all services permanently connected to it before commis-sioning is requested.

For completion by Plantroom Attendant

For technical, servicing or parts enquiries, telephone, fax or email to Hoval Ltd quoting the calorifier(s)

serial number, as above.

4 Description of CT-plus Calorifier

• Suitable for use with any make of boiler• High efficiency heat transfer for rapid

D.H.W. regeneration.• Recirculation design removes danger of

temperature stratification.• Optimum D.H.W. storage - sufficient for quick

draw-off but with lower standing losses thanconventional large volume calorifiers.

• Low level connection for complete draining and flushing out. (CIBSE TM 13:2000 Recommendations to prevent Legionella Bacteria Contamination).

• Very low primary and secondary resistances.

• An electric immersion heater can be fitted by prior arrangement (three phase supply only).

• Large heating surface, suitable for operation with lower temperature primary feed from condensing boilers.

• See page 10 for unvented systems and the additional equipment required.

Internal view of CT-plus eco Calorifier

1. Primary Inlet2. Primary Outlet3. Cold feed4. Secondary Flow5. Secondary Return6. Drain7. Primary air release

cock8. High efficiency

insulation

9. Non-corrosive stainlesssteel cylinder

10. Special “ripple” innershell to enhanceheat transfer

11. Primary watersurrounds DHWcylinder

12. Thermostat(s)13. Inspection and cleaning

cover or plugged 2.1/4”inspection socket

(CT-plus eco 280-520)

7 4 1213

1

2

8

10

3

9

6 5

11

T&P valve on unvented calori ers only

4214941-02March 2018

Description of CT-plus Calorifier

ApplicationsCT-plus eco calorifiers are designed to operate with the full range of Hoval boilers up to 3.10 Bar pri-mary pressure, and are intended for the produc-tion and supply of DHW to commercial and indus-trial premises.The CT-plus eco is available in four model sizes with high performance outputs up to 1590 litres per hour.An ErP energy rating applies to models CT-plus eco 180, 280 & 420 (see page 5).General DetailsThe construction of the CT-plus eco is in the form of a vertical, free standing unit, comprising a high grade stainless steel inner vessel with a “rippled” wall to enhance heat exchanger efficiency. This is sur-rounded by a mild steel primary water jacket, which is encased with a 120mm thick insulated jacket. The assembly is mounted on four legs with the primary flow and return connections on the side. On all four models, the secondary flow is from the top and the smallest model (CT-plus eco 180) also has the secondary return and cold feed connections at the top. For the three larger models, all the con-nections other than secondary flow are at the base.

Performance of the four CT-plus eco models covers a range of outputs up to an hourly rating of 1590 litres/hour. Higher outputs can be provided by ar-ranging the units in modular formation. For most typical applications (other than process water generation) the key requirement is for adequate quantities of hot water over a relatively short period. On this basis, the CT-plus eco will provide significantly higher flow rates than its continuous hourly rate.

Key Features

5

Dimensions

Model A B C D E F G Inlet2 3 4 7

Lifting

1807

1904

1904

2300

753

853

943

943

346

346

346

346

1030

1280

1280

1676

138

85

85

85

165

120

120

120

90

85

85

85

1 1” 1” ” 1” ” 1 ” 1/ ”

1.1/4” 1.1/4”1.1/2”

1.1/2”

1.1/2”

1.1/2”

1.1/2”

1.1/2”

1.1/2”

1.1/2”

1.1/2”

1.1/2”

1.1/2”

1.1/2”

1.1/2”

1”

1”

1”

***

Position of electrical connectionsto thermostat. 240v 1 phase 50Hz * 2 No. lifting lugs provided on top plate.

Connection 9 - Primary air release cock.

Primary SecondaryConnections - BSP Male

CT plus eco 180

CT plus eco 280

CT plus eco 420

CT plus eco 520

Water Content WeightPrimary

litresSecondary

litresDrykg

Wetkg

61 180 177 418

94 280 211 585

114 420 248 782

135 520 302 957

Working Pressures.System. Max Working Pressure. Test Pressure.Primary 3.10 bar 5.18 bar

Working Temperatures.System. Normal Temp. Max Temp.

Primary 82 C 90 Co

oo

o

Secondary 6.00 bar 9.00 bar

Secondary 60 C 70 C

ModelCT plus eco 180

CT plus eco 280

CT plus eco 420

CT plus eco 520

Both sides flooded.

Technical and Performance Details

C

C

C

ErP energy rating classification.

Technical and Performance Details CT-plus eco Calorifier

8 91 5 6Outlet Cold feed Flow Return Drain T&P Valve Air release

1.1/4”

1.1/2”

1.1/2”

1/ ”

1/ ”

1/ ”

2

34

5

6

7

1

2

CT plus eco 180 CT plus eco 280-520

PLAN VIEW PLAN VIEW

4 35

7

9

T&P valve connectionfor unvented calorifiers(optional)

T&P valve connectionfor unvented calorifiers(optional)

Fit an anti-thermal loop to cold feed.

Pipe sizes can be expanded to suit site requirements if necessary on leaving the calorifier.

March 2018 4214941-02

EF

EFFE

93mm 93mm

* *

6 Outputs Based on 10oC Cold Feed, 82oC Primary Flow and 60oC Secondary Flow.

Model at dif

Hydraulic Resistanceat dif

Primary SecondaryFlow rate l/s Resistance mbar Flow rate l/s Resistance mbar

CT plus eco 180

CT plus eco 420

CT plus eco 280

CT plus eco 520

litres/secondContinuous hourly

draw off litres10 mins draw off

litres 0.751.121.50

180

1.502.50

7201000 280

1.502.002.78

96012501365

420

520550590

1.502.002.78

103713371590

520

0.751.121.50

1.502.50

1.502.002.781.502.002.78

3578

140

1550

152363132363

0.751.121.50

1.502.00

1.502.002.501.502.002.50

3067

120

1832

2645704071111

*

f .

f

Rating kW = Q x S.H. x (T2 - T1 )

Q = T1 = T C T2 = T C

= C

To calculate the load on the boiler for y.

Note for Hydraulic Testing: The primary jacket should not be pressurised without

steel vessel.

An adjustable secondary thermostat has a sensing point which ensures that the main body of water is held uniformly,

set level, normally 60oC - 65oC.

DHW Output

*Primary and Secondary Hydraulic Resistance.

3600

Model

CT plus eco 180

CT plus eco 420

CT plus eco 280

CT plus eco 520

Legionellae r

er r er shown above

Technical and Performance Details

When temporarily operating the primary side only, the pressure should not exceed 1 bar g and the secondary side should be vented.

Chloride!

!!

!!

March 8 2

7

A B

1

AAV 2

3

4

5

3

36

Primary Connections from Main Headers. Temperature control by pump.

Primary Water

Secondary Water

Anti-thermal loop

1

AAV 5

4 (if Required)

36

Primary Connections from Main Headers. Temperature control by diverting valve.

3

7

Primary Water

SecondaryWater


InstallationPosition the calori ers as required, ensuring that side and inspection opening clearances are adequate. Fit unions to all pipe connections ensuring that joint seals are Fit isolating valves to all pipework.


Note: The CT-plus calor er is with a separate DHW drain

tapping. The primary drain must be tted off the primary outlet connection in the site pipework.

Piping layoutFor the general design of water circuits refer to current British Standards and Codes of Practice. A simple pumped primary and return, ad-equately vented, is all that is needed. Secondary

To facilitate venting during drain down on unvented secondary systems, ensure that a manual vent valve is in the second-ary w between the calori er and the isolating valve. On open vented systems the vent should be taken from the same place.

Recommended Primary Systems (Open vented DHW system)

Key(1) Safety Valve recommended if noton adjacent boiler or system.(2) Spring loaded non-return valve.(3) Isolating valves.(4) Primary pump (For diagram “B”the main circulating pump may be

(5) Thermostat (linked to primarypump to control calori er DHWtemperature, for Diagram A).Fordiagram B the thermostat controlsthe diverting valve.(6) Drain cock.(7) Diverting valve (use 30 secondmotor).

Note:On Unvented systems there is a high temperature limit thermostat tted. The installer should wire this back to the control valve / primary pump and also a 2 port motorized valve. This should be on the primary inlet, to stop the w of primary water entering the calori er in the event of a high temperature condition.

connections are quite conventional. Connect the calori er(s) to the rest of the system according to the chosen layout. Examples of both primary and secondary systems are shown below:

! !

March 2018 4214941-02

8 Installation and Piping Layouts

C D

1

AAV

2

3

4

5

3

3 6

Primary Connections direct from boiler. Temperature control by pump.

Primary Water

Secondary Water

Flow

Return

Boiler

Anti-thermal loop

3

1

AAV 5

4 (if Required)

6

Primary Connections direct from boiler. Temperature control by diverting valve.

3

7

Primary Water

SecondaryWater

Return

3

Flow

Boiler

3

3

Boiler

Recommended Primary Systems Continued

Key(1) Safety Valve recommended if noton adjacent boiler or system.(2) Spring loaded non-return valve.(3) Isolating valves.(4) Primary pump (For diagram “D”the main circulating pump may be

(5) Thermostat (linked to primarypump to control calori er DHWtemperature, diagram C). Fordiagram D the thermostat controlsthe diverting valve.(6) Drain cock(7) Diverting valve (use 30 secondmotor).

Recommended Secondary Systems

Key(1) Relief valve adjacent to calori er.(2) Spring loaded non-return valve. Note: On CT-plus eco 180 the

secondary return and cold feed connections are at the top. The cold feed should be taken to a low level thermal syphon to avoid thermal circulation up the cold feed.

(3) Isolating valves.(4) Open vent.(5) Unvented system kit.(6) Secondary drain valve.

AAV

Secondary Connections OPEN VENTED.

Primary Water

SecondaryWater

1

2 3 3

3 3 6

Vent

Cold Feed

Secondary Return

31

4Manual Vent Valve

T & P Relief Valve

Secondary Connections UNVENTED.

Primary Water

SecondaryWater

2 3 33 36

Cold Feed

Secondary Return

3

5

35

2

Note:On Unvented systems there is a high temperature limit thermostat tted. The installer should wire this back to the control valve / primary pump and also a 2 port motorized valve. This should be on the primary inlet, to stop the w of primary water entering the calori er in the event of a high temperature condition.

March 2018 4214941-02

9Unvented Systems

An unvented hot water system differs from conventionalopen vented systems in that no vent pipe is providedand it is connected to the mains water supply, eliminatingthe need for the provision of cold water storage tanks inthe roof space. The functions, therefore, of the openvents and cold feeds have to be performed in otherways. There are two basic types of unvented system:(1) Direct off the mains,(2) Boosted water supply.

Direct off the mainsWhere mains pressure is sufficient the system can be connected straight off the mains. However, between the cold water supply and the DHW generator (i.e. the CT-plus eco calorifier) there must be an unvented system kit fitted.

Warning: Some pressure boostersets have an accumulator (expan-sion vessel). This is to reduce theamount of pump starts and shouldnot be confused with the systemexpansion vessel.

This kit should contain a minimum of the followingitems:-• An expansion vessel should be fitted between the

non-return valve and the calorifier to take up expandedwater during heat-up.

• An expansion relief valve should be fitted in the coldfeed between the expansion vessel and the calorifier.No means of isolating the calorifier from this valveshould be installed.

• A temperature and pressure relief valve should befitted directly in the calorifier as a thermal protectionto prevent the DHW reaching 100 deg C.

• A hand reset limit stat should be fitted in the calorifierto prevent the DHW overheating.

Balanced Unvented SystemsSome systems may be fitted with blending valves ormixers that require a balanced hot and cold watersupply. When sizing the strainer, the PRV, and checkvalve care must be taken to ensure they can pass theflow rates at the required pressure.Hovals’ standard unvented system kits are sized toreduced incoming pressure to 3 bar at a flow rate thatmeets the peak output of the calorifier only.

As shown in the above diagram, an unvented system kitcomprises of the following components:-• Strainer (this is optional, but good practice, to prevent

debris passing through the valves)• Pressure regulating valve (PRV), this allows the

pressure to be reduced and controlled at a presetpressure. A pressure gauge is supplied to indicatesystem pressure.

• Double non return valve, this prevents the expandedwater back-feeding into the mains supply andsubsequently seals the system.

• An expansion vessel should be fitted between the nonreturn valve and the calorifier to take up expandedwater during heat-up.

• An expansion relief valve should be fitted in the coldfeed between the expansion vessel and the calorifier.No means of isolating the calorifier from this valveshould be installed.

• A temperature and pressure relief valve should befitted directly in the calorifier as a thermal protectionto prevent the DHW reaching 100 deg C.

• A hand reset limit stat should be fitted in the calorifierto prevent the DHW overheating.

Boosted water supplyWhere mains water pressure is insufficient a coldwater booster set can be fitted. Normally these setshave integral pressure controls, in the form of eitherpressure transducers, pressure switches, and orpressure regulating valves. They also have a non returnvalve which prevents back-feeding. Systems where abooster set is installed should not have a vent and assuch are unvented.Boosted systems should have an unvented system kitfitted down-stream from the booster set.

T & P Relief Valve.

Control & hand reset limit stats.

Expansion relief valve c/w tundish.

Expansion Vessel.

Check valve.

PRV.

Strainer.

Unvented System Kit.

Cold Feed

March 2018 4214941-02

Unvented Systems

10

60 litre ¾” HP60-1”

Strainer P.R.V.

DoubleCheckValve

ExpansionVessel

ExpansionRelief

Valve &Tundish

T & PReliefValve*

T & P Relief Valve.

Control & hand reset limit stats.

Expansion relief valve c/w tundish.

Expansion Vessel.

Check valve.

PRV.

Strainer.

Unvented System Kit.

Cold Feed

60 litre ¾”

CT-plus eco 420 1” 1” 1” 80 litre ¾” 1”

CT-plus eco 520 1” 1” 1” 80 litre ¾” 1”

Warning: On balanced systemswith a common PRV, Strainer andDouble check valve, ensure thatthe valves are sufficiently sizedto cope with both hot and coldwater demand.

A separate Strainer and PRV can be fitted to both the hot and cold water services to give balanced system pressures. Alternatively, a larger Strainer and PRV can be installed to cope with both hot and cold water demands.Cold water booster sets tend to be sized on the total demand of the system and subsequently give a balanced condition.

Hoval Unvented System Kits

Hoval have carefully sized and selected a range of standard unvented system kits suitable for installation with the CT-plus eco range of calorifiers.

The various valves and fittings should be installed in the sequence shown on the right.

The size of the standard unvented kits are shown in the table below.

Please note that these kits are only sized for the cold feed going into one of the CT-plus eco calorifiers.

Using the PRV from a standard Hoval unvented kit to provide a balanced hot and cold water supply may cause pressure and water flow problems. Ensure that the PRV can cope with the demand from both the hot and cold water services.

Unvented Systems

HP80-1”

HP80-1”

1”

1.1/4”

1.1/2”

(Supplied with

*Supplied factory tted with unvented calori er

4214941-02March 2018

(discharge pipe(s) by others - not supplied by Hoval).

CT-plus eco 180 ¾”

CT-plus eco 280 ¾”

¾”

¾” HP60-1”

22mmDC222mmDC2

1.1/2”

Items in the Unvented System Kit

Cal

orifi

er

Mod

el

Kit R

efer

ence

11

Common Unvented System Kit.

Cold Feed

More than one calorifier can be installed off a single common cold feed. Each calorifier must have it’s own T & P valve and expansion relief valve. No means of isolating these safety valves from the calorifier should be installed.

Drain Cock By the Installer

Strainer

Pressure Reducing Valve Double

Check Valve

Expansion Vessel

Expansion Relief Valve and Tundish


Temperature and Pressure Relief Valve


Isolating Valve

Isolating Valve

Shared Unvented System Kits Feeding two or more calorifiers.

Cold Feed

Two or more calorifiers can be installed with individual unvented system kits. Where the expansion vessels have been sized to share the total system expansion the two feed lines can be joined by a pipe to allow both vessels to be used when one calorifier is isolated.


Strainer


Check Valve

Expansion Vessel





Isolating Valve

Isolating Valve

Strainer


Check Valve

Expansion Vessel

Cold Feed


Joining pipe.

Multi-calorifier Installations

Unvented Systems

Joining pipe

March 2018 4214941-02

12

Balanced hot and cold water services using two PRVs.

Cold Feed

The hot and cold water supplies can be balanced using two separate PRVs.


Strainer

Pressure Reducing Valve

Double Check Valve

Expansion Vessel



Isolating Valve

Balanced Cold Water Supply

Balanced Hot and Cold water supplies.

Unvented Systems

Unvented System with balancedhot and cold water services.

Cold Feed

The hot and cold water supplies can be balanced by utilizing the same strainer and PRV to control the two supply lines. Note it may be necessary to increase the size of these two fittings in comparison to the non-return valve in the calorifier cold feed line.


Strainer


Check Valve

Expansion Vessel



Isolating Valve

Balanced Cold Water Supply

March 2018 4214941-02

13

Fitting the Unvented System Kit.

Fit the components as indicated. In the suggestedschematics detailed on previous pages.

All components must be installed in a frost free area.

Ensure that valves and fittings are fitted correctly tosuit the direction of flow.

Set the Pressure reducing valve (PRV) to 3 bar.

Pipe off expansion relief valve via the tundish providedto a gulley.

Pipe expansion vessel into cold feed. Fit a lock shieldvalve and drain between the vessel and the cold feedline. This will allow the expansion vessel gas charge tobe checked during maintenance. This is shown on theright.

Installation of the Expansion Vessel.

Cold Feed

Fit a lock shield valve and drain to allow the expansion vessel to be isolated and drained for periodic inspection. Drain Cock

(By the Installer)

Strainer


Check Valve

Expansion Vessel

Lock Shield Valve (By the Installer)

Maintenance of Unvented System Kit.

Clean out strainer on commissioning and annually.

Check Expansion relief valve setting annually bytwisting the cap on top of the valve.

Check expansion vessel gas charge pressure, isolatethe vessel, drain off any water in the vessel and test thegas pressure using a tyre gauge.

Fault Finding.

Symptom Possible Cause(s) Remedial Action

(A) Reduction in water flow Blockage in strainer Clean out strainer.Blockage in PRV Clean out secondary strainer in PRV.Wrong PRV pressure setting Check PRV pressure setting alter if necessary.

(B)Discharge from expansion Debris on valve seat Twist test knob and replace if necessary. Relief valve. Wrong incoming pressure Adjust the pressure setting on PRV.

Expansion vessel diaphram Check expansion vessel gas charge.Failure.Insufficient Expansion vessel Check expansion vessel size.volume.

Expansion Vessel Sizing.Expansion Vessel Volume = System content (l) x C.o.E.

Vessel Efficiency

Vessel Efficiency = Max Pressure (Bar Abs) - Min Pressure (Bar Abs) Max Pressure (Bar Abs)

Where: Max Pressure is final desired working pressure + 1.Min Pressure is pressure setting on PRV + 1.C.o.E. at 60 Deg C is approx 0.02

Unvented Systems

March 2018 4214941-02

14

Commissioning Instructions

• Flush all swarf, filings and other debris out ofthe system, preferably using a proprietary flush-ing agent. Do not wash particles into the calorifier,this could cause subsequent corrosion.• Once the secondary side is fully flooded andsealed, fill the primary system completely andtreat the water with a good corrosion inhibitor(e.g. Fernox). Corrosion inhibitors are not usedin secondary (tap) water.• Ensure that all joints are water tight and allpipework is vented.• Check that all electrical connections are com-plete and correct.•Ensure that the thermostat(s) are wired up andthe sensor probes are fitted in the stat pocket.The thermostat may be wired into the boiler con-trols to activate the pumps or a motorised valve.The control thermostat can be adjusted to oper-ate between 30 deg C and 80 deg C and is usu-ally set to 60 deg C.

Pre-commissioning:

Important: Always fill the second-ary side of the calorifier beforethe primary. Pressurising the pri-mary when the secondary isempty may cause the secondarybottle to collapse.

Commissioning

(1) Light the boiler (refer to the appropriate boileroperating instructions).(2) Adjust the calorifier thermostat to the requiredoperating temperature.(3) Check that the thermostat is operating cor-rectly.(4) Ensure that the primary pump is working orprimary primary circuit is established.(5) Check that the operating temperature remainsconstant.

Operating Instructions

The calorifier thermostat when wired to the pri-mary circulating pump or diverting valve providescompletely automatic control. It is necessary onlyto adjust the thermostat if the occasion demands.

Warning: To avoid Legionellae, en-sure the calorifier control stat is setat a minimum of 60 deg C.


March 2018 4214941-02


15

Periodic Inspection

CleaningThe period between cleaning will depend on op-erating temperature and hardness of water. Lo-cal conditions will serve as a guide. Normally de-scaling will be required less often than with con-ventional calorifiers.

The following procedure should be adopted:

(1) Remove calorifier top casing panel.(2) Remove cleanout cover or inspection socket plugto access the calorifier internals.(3) Scrape the inside surface with a non ferrousscraper.

Note: Chemical cleaning can be carried out if re-quired, but such work should be undertaken in accordance with the instructions of the de-scal-ing compound manufacturer.

After chemically cleaning the DHW calorifer internal, ensure that the unit is thoroughly flushed out with clean water.

Following cleaning, replace cleanout cover us-ing a new gasket to prevent leaks or refit the inspection socket plug and seal accordingly.

Inspection and Maintenance

Draining Down

(1) Ensure that both primary and secondarypumps are switched off.(2) Isolate the primary inlet and outlet.(3) Fit hose to primary drain which should be in-stalled in primary outlet and run the hose toa gulley.

Note: The primary side of thecalorifier MUST always bedrained before the secondary.The secondary MUST always befilled before the primary.

Draining the calorifier downshould be done by following theprocedure below:-

When filling the calorifierfollow the above procedurebut in reverse.

The user is advised to carry out periodic inspec-tion between main servicing periods and it is rec-ommended that the specialist servicing companyalso carries them out.

• Inspect the calorifier casing for obvious signsof damage, corrosion or deterioration.• Inspect the calorifier siting for signs of crack-ing or settling.• Inspect all pipes and connections for obviousdamage or deterioration.• Remove calorifier top panel and examine in-terior for corrosion and deterioration.

(4) Open primary vent valve.(5) Open primary drain.(6) Isolate all secondary connections.(7) Fit hose to the secondary drain which is lo-cated underneath the calorifier and run the hoseto a gulley.(8) (On sealed systems) Open manual second-ary vent valve (this should be fitted in secondaryflow between calorifier and isolating valve).(9) Open secondary drain valve.

Model Joint Cat No.

CT plus 180 414035

CT plus 280-520 414007

4214941-02March 2018

Inspection & Maintenance

Note: For all CT-plus eco calorifiers supplied before November 2017 and new CT-plus eco 180 & 280 calorifiers - before opening the inspection cover always ensure you have a spare inspection cover joint.

16 Immersion Heaters

General• All work should be carried out by suitably qualified

personnel.• Heaters must be handled with care and stored in

dry conditions.• Adequate withdrawal space must be provided to

allow the removal of the heater assembly.• Carefully remove all protective packaging and

visually inspect unit for any transit damage.• All prevailing rules, regulations and bylaws in force

at the time and place of installation must beobserved.

• Heaters must only be immersed in the fluid theyare designed to heat.

• The introduction of alternative fluids even in smallconcentrations for purposes such as sterilisingmay cause serious damage to the heater and willinvalidate the warranty.

• Any modification not carried out by Heatex Limitedor its approved agent will invalidate certificationand warranty.

• Precautions must be taken to prevent damage toenclosure seals.

Installation• The heater should be securely fixed in position and

all terminal connections checked for tightnessbefore energising.

• The installed orientation of horizontally mountedheaters must be such that any thermostats orother temperature sensors are uppermost.

• Sealing gaskets must be undamaged.• The terminal box must not be used for tightening

heater into tank or vessel.

Electrical Supply Connection• Refer to wiring diagram on page 17.• The cable entry or gland plate is positioned on the

side of the terminal box.• Before connection ensure that the supply

corresponds with that specified on the rating label.• Ensure that the sizes and types of cables to be

used are suitably rated for the load and temperatureof the unit.

• Each heater must be protected by a suitably ratedover current device.

• The cables must enter the heater terminal box viaa suitable cable gland to maintain the IP rating andbe fitted by a qualified person.

Earth Connection

Operation• Ensure that the active sections of all the heating

elements are fully immersed in the fluid to beheated at all times whilst energized.

• Heat is transferred by means of electric heatingelements.

• Control of the heater is facilitated bythermostats, thermocouples or RTDs andreference should be made to the wiring diagraminside cover to ensure that these are correctlyconnected and set prior to energising the heater.

• Where a manual reset thermostat or cut-out isinstalled, the terminal box cover will have to beremoved after isolating the heater to enable areset to be carried out.

THESE HEATERS MUST BE EARTHEDAn earth connection is provid-ed inside the terminal box.

Routine Maintenance

Maintenance• All prevailing site safety regulations shall be

adhered to at all times.• Equipment is to be fully isolated from the

electrical supply and locked off before and whilstany work is being carried out.

3 Monthly• Generally inspect the equipment for external

damage or leaks.

6 Monthly• Isolate the electrical supply and remove the

cover.• Ensure the terminal box is clean and dry

internally.• Ensure the electrical terminals are intact and

secure.• Check that the heating element insulation

resistance is at least 2 mega ohms.• Check the continuity of all elements.• Refit cover with new gasket if required.• Ensure that earth continuity is maintained

between all exposed conductive material andmain site structure.

Annually• Carry out all 3 monthly and 6 monthly checks

as above.• Check for element failure or low insulation

resistance.

• If heaters are being left unused for a periodgreater than 3 months, carry out 6 monthlymaintenance before energizing.

March 2018 4214941-02

Immersion heaters

17Immersion heater Electrical Diagram

March 2018 4214941-02

Immersion heater wiring diagram

18 Fault finding

Please carry out checks as per the list below when faults occur. If you cannot rectify the fault,contact Hoval Customer Services or your installer. Telephone number and e-mail addressare shown on the rear cover.

Symptom Possible Cause Action

A. Primary WaterCircuit Inefficient

(1) Leakage in system.

(2) Pump faulty or inoperative.

(3) Boiler faulty or inoperative.

(4) Circuit not properly vented.

(5) Pump not of sufficient duty.

(1) Check pipe connection. Renewif required.

(2) Refer to appropriate pump partdocument.

(3) Refer to appropriate boiler partdocument.

(4) Vent primary system.

(5) Change pump speed or pump.

Symptom Possible Cause Action

A. Secondary watertemperature not assetting on thermostat.

(1) Leakage in system.

(2) Pump faulty or inoperative.

(3) Thermostat faulty.

(4) Electrical fault in control system.

(5) Calorifier scaled up.

(6) Calorifier not large enough for loadimposed.

(7) Low primary temperature.

(8) Diverting valve bypassing.

(1) Check pipe connection. Renewif required.

(2) Refer to appropriate pump partdocument.

(3) Check and replace if required.

(4) Refer to appropriate control sys-tem part document.

(5) Mechanically / chemically de-scale as necessary.

(6) Change calorifier or add calorifi-er / buffer vessel.

(7) Turn up boiler thermostats / in-crease primary flow rate.

(8) Check primary pipe cools whenhot.Water not required.

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Fault Finding Chart

19Electrical Diagrams

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Wiring Diagrams for Open Vented Calorifiers

20 Electrical Diagrams

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Wiring Diagram for Unvented Calorifiers

21Notes

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Conservation of EnergyProtection of the Environment

Hoval Limited, Northgate, Newark, Notts NG24 1JNTelephone: Service Desk - 01636 593413

Spares Desk - 01636 593412Fax - 01636 673532

e-mail: [email protected] and [email protected] Site: www.hoval.co.uk

March 2018 4214941-02

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