tm025 rheem 310 series heat pump rev b.pdf

8/10/2019 TM025 Rheem 310 Series Heat Pump REV B.pdf

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SERVICE INSTRUCTIONS

310 Series Heat PumpTM025

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551310


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TM025 Rheem Heat Pump Service Instructions REV: BDate of Issue: 02/08/07


1

Contents

Safety Warning ....................................................................................................................2Introduction..........................................................................................................................2Specifications.......................................................................................................................3Preventative Maintenance ...................................................................................................3Operation.............................................................................................................................4

Electronic Controller ............................................................................................................5Operating Sequence Flow Charts:.......................................................................................6

Refrigeration Terms and their Meaning................................................................................8Components and their Function...........................................................................................8Common Faults ...................................................................................................................9Wiring Diagram..................................................................................................................11Refrigeration Sealed System Diagram...............................................................................12LED Indication ...................................................................................................................12Fault Finding ......................................................................................................................14Refrigerant Charge ............................................................................................................45Electrical Insulation Testing ...............................................................................................46

Component Replacement Procedures Water Heater......................................................47

Component Replacement Procedures Refrigeration Plant .............................................52Component Replacement Procedures Sealed Refrigeration System .............................57Exploded View - Refrigeration Plant ..................................................................................62

Replacement Parts List Refrigeration Plant.................................................................63Exploded View - Water Heater...........................................................................................64

Replacement Parts List Water Heater .........................................................................65Rheem Electric Water Heater Warranty - (Australia Only) .................................................66Document Revision History................................................................................................67


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2

Safety Warning

The purpose of this Service Manual is to provide sufficient information to allow a personwith the skills as required by the controlling Regulatory Authorities to carry out effectiverepairs to a Rheem 310 series Heat Pump Water Heater in the minimum of time.

Safety precautions or areas where extra care should be observed when conducting testsoutlined in this manual are indicated by print in bold italics and/or a warning symbol.Take

care to observe the recommended procedure.

Certain diagnostic procedures outlined in these service instructions require live testing to be conducted. Wear Personal Protective Equipment (PPE)when conducting these tests to prevent the risk of electric shock. (Refer tothe Rheem Safety Procedure on electr ical testing)

R134A is a controlled substance under the fair trading act. Personnelqualified and licensed to work with refrigerants may only carry out serviceand repair to the sealed refrigeration system. During repair the refrigerantmust be recovered, not vented to atmosphere.

Environmental

At the end of the service li fe o f a Rheem heat pump the refr igerant must berecovered by personnel qualified and licensed to work with refrigerantsprior to the unit being disposed of. Refrigerants must not be vented toatmosphere.

Introduction

The information provided in these instructions is based on the water heater being installedin accordance with the Installation Instructions provided with each water heater.

Should you require further technical advice on a Rheem 310 Series Heat Pump WaterHeater, contact your nearest Rheem Service Department where all genuine replacementparts are also available.

Heater Model Identification

All identification numbers are designed to convey detailed information about the waterheater to which it is attached. The model number consists of 8 digits.

5 X X 310 0 X

5 Renewable Energy Model

5 Air Sourced9 Solar Sourced

0 No Heating Units1 Booster Element

Storage Capacity in Litres

No Reference System Requirement

0 Element Not fitted5 2400 watts7 3600 watts

Note: Model number, serial number and date of manufacture should be quoted in allcorrespondence.


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3

Specifications

Water Heater

Model 551310Capacity - Litres 310

Boost Capacity - Litres 220

Booster element rating - kW 2.4 or 3.6T&PR valve Rating - kPa 1000

With ECV 680Maximum inlet pressure - kPa

Without ECV 800

Inlet / Outlet RP/20Water Connections

T&PR RP/15Quantity 1

AnodeLength 1153

Control board thermostat setting (fixed) 60C

Limp mode mechanical thermostat setting 70C

Mechanical thermostat ECO setting 88C

Refrigeration System

Parameter 551310

Sound rating 51 dBA @1.5mSuperheat setting (Factory) +6C at 10C Evaporator temp.Refrigerant charge R134A 1050 gramsCompressor internal OTC Open 150C. Close 90C (automatic reset)

Compressor winding resistanceRun winding - Red & Blue: 2.2 ohms at 20C

Start winding - Red & Black: 3.27 ohms at 20C

Compressor Capacitor 35F240 VAC 50HZ

Fan winding resistanceRun winding Black & Brown: 184 ohms at 20CStart winding Black & Blue: 238 ohms at 20C

Fan Capacitor 2F240 VAC 50HZ

Circulator winding resistance 75.3 ohms @ 20C

Preventative Maintenance

It is suggested for peak performance that the water heater be serviced annually.

1. Check for discharge from the T&PR valve. When the element or heat pump isoperating a small discharge of water may be evident. Operate the valve-easing lever toensure the valve opens and resets properly. Always open and close the valve gently.The T&PR valve should be replaced at 5 yearly intervals.

2. Check for leaks at all cylinder fittings.

3. Check for signs of excessive corrosion on the water heater jacket.

4. Isolate power to the water heater and check all electrical connections for signs ofoverheating due to poor connection.

5. Conduct an 'Electrical insulation test' on the water heater (refer to page 46).

6. Check evaporator fins and fan blade for build up of dust or debris.

7. Check for sludge build up and if necessary drain and flush tank.


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4

Operation

Operation Water System:

The heat pump utilises a form of heating called top down heating.The circulator (1)draws cooler water from the bottom of the cylindervia the long dropper tube (2). The water passes through the heatexchanger (condenser) (3)where it is heated by the refrigerant and isthen returned to the top of the cylinder via a short dropper tube (4).

Operation Heat Pump Mode:

During normal operation in heat pumpmode the electronic controller(control board) holds a control relay in the energised state and powerfor the compressor is passed to an electronic switch (called a triac) viathe normally open relay contact.

The operation of the compressor causes a pressure difference withinthe sealed refrigeration system. This pressure difference causes the

refrigerant to move around the sealed system. The refrigerant entersthe evaporator (5)as a liquid, as the refrigerant absorbs heat from theatmosphere it changes state, at low pressure, from a sub cooled liquidto a super heated vapour or gas (evaporates). The vapour then entersthe compressor (6) and obtains more heat, known as heat ofcompression, and passes into the heat exchanger as a super heatedvapour at high pressure.

As the refrigerant passes through the heat exchanger it gives offheat which is absorbed by the water flowing through a separatechamber inside the heat exchanger. As the refrigerant gives offheat it cools and changes state back into a liquid (condenses). Therefrigerant then enters the evaporator again and the cycle isrepeated.

Operation Boost Mode:

The controller will enter boostmode when atmospheric conditions are unsuitable for heatpump operation or a possible failure of the refrigeration or water circuits has beendetected. The following error conditions will initiate boostmode:

1. The temperature sensed by the ambient air sensor is below 0C.

2. The water leaving the heat exchanger is greater than 80C.

3. The compressor discharge temperature is greater than 110C.

4. The evaporator temperature is less than -3C.

5. The failure of sensors S3, S4 or S5.

6. The compressor is not running based on either of the following conditions:

a. After 2 minutes in controller sequence 3 the compressor discharge temperature hasnot risen 15C above ambient.

b. In controller sequence 4 the water temperature rise across the heat exchanger(condenser) is less than 8C.

Inboost

mode the electronic controller continues to control the temperature of the water inthe cylinder and the circulator however the control relay is de-energised switching thepower supply from the compressor triac to the element.

1

2

3

4

3

6

5


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5

Boostmode allows 220 litres of 60C hot water to be provided by electric boosting. Duringthis mode the circulator will cycle on and off periodically allowing for the 220 litre boostcapacity rather than just the amount of water above the element as is the case with aconventional electric boost system.

Once a heating cycle is completed the error is cleared and normal operation is resumed onthe next call for heat.

Note: If sensor S4 fails the system will operate on boost mode however the temperaturewill in this case be controlled by the mechanical thermostat and 220 litres of 70C waterwill be available.

Operation Limp Mode:

Limpmode will only occur due to the failure of both sensors S1 and S4.

In limpmode the electronic controller no longer controls the operation of the heat pumpand both heat pump mode and boostmode are rendered inoperable. The control relay isde-energised switching the power supply from the compressor triac to the element.

Limpmode allows 111 litres of hot water to be provided by electric boosting and the water

temperature is controlled by the mechanical thermostat which is set to 70C; in thiscondition only the water in the zone above the element is heated as the circulator does notoperate.

It should be noted that if sensor S1 fails and sensor S4 is operational the system operatesin boost mode however the circulator cannot operate. In this case the end result is anoperation similar to limp mode in which 111 litres of water is heated by the booster and thetemperature controlled to 70C by the Robertshaw thermostat.

Electronic Controller

The main features of the electronic controller(control board) are shown on the diagram opposite.The inputs to the software are shown in blue andthe outputs that control the heat pump are shown inred.

The connection marked relay element energisesor de-energises a relay that switches from heatpump heating to electric element heating when thesystem operates in boost or limp mode.

The Compressor TRIAC switches the power to the

compressor on and off.The Communication port can be used inconjunction with a computer to read the inputs andoutputs from the software. This information may belogged using specially designed logging software(Contact Rheem Service for more informationregarding this software).

The Software loading port is only used for loadingsoftware on to the control board.

The green and red LEDs indicate the condition ofthe heat pump (refer to the section titled LEDIndication on page 12).


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7

Page 2 of 2:

NO

Boost Mode

220L heated toapprox. 60C

H

Relay de-energised

Red LED Flashing

Element On

S1>62C?

S4>53C?

YES

NO

Element OffYES

Z

Circulator On

NO

S153C?

YES Circulator Off

YES

NO

Sequence

0

YES

S4Sensor

ok?

Temp atthermostat =

70C?

Controller can no longer detect

lower cylinder temperature.Water temperature will becontrolled by mechanical

thermostat to 70C

S1Sensor

ok?

NO

YES

Controller can no longer detect

upper cylinder temperature.

The circulator will not operatepreventing water below theelement level from heating

Temperature at sensor S4 willnot achieve 53C

NO

Heating Cycle

complete

Element On

Limp Mode

111L heated to

approx. 70C

NO

Element Off

YES

Power to controller offY

S1Sensor

ok?

S1>62C?

YES

Boost Mode

220L heated to

approx. 70C

Circulator On

Temp atthermostat =

70C?

YES

S1 2C?

T4> 2C?

A

YES

NO

NO Ambient temperature high enoughto resume heat pump operation

YES


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8

Refrigeration Terms and their Meaning

Sub Cooled Liquid A substance below its saturation temperature at a given pressure.

Super Heated VapourA substance above its boiling point at a given pressure.

Saturated Vapour A substance at its boiling point at a given pressure.

Latent Heat Hidden (invisible) heat removed or added to a substance that results in achange of state (i.e. liquid to a vapour) without an increase or decrease in temperature.

Heat of Compression The additional heat added to a substance by the act ofcompressing it.

Low Side Components and pipe work of a refrigeration system operating at lowpressure, generally considered to be the evaporator, suction line and accumulator.

High Side Components and pipe work of a refrigeration system operating at highpressure, generally considered to be the condenser, discharge line, liquid receiver/filterdrier and compressor case where a rotary compressor is utilized.

Boil Off The action of a substance as it absorbs heat and changes state (evaporates)from a liquid to a vapour (gas).

Give Up Heat The action of a substance as it releases heat and changes state(condenses) from a vapour (gas) to a liquid.

Components and their Function

Temperature and Pressure Relief Valve - A valve designed to provide automatic relief bydischarging water in case of excessive temperature, pressure or both.

Never fit a T&PR Valve with a pressure rating greater than that indicated onthe product-rating label.

Pressure Limiting Valve (P.L.V.) - A valve that controls its outlet pressure to apredetermined limit.

Outlet Delivery Tube (Dip Tube) - A plastic tube installed in the hot water outlet of thewater heater cylinder to conduct water from the highest point to the outlet connection. Italso acts as a fitting liner.

Diffuser- A plastic device installed in the cold water inlet of the water heater cylinder toassist with stratification. It also acts as a fitting liner.

Fitting Liner - A plastic tube installed in the cold-water inlet of the water heater to provideprotection against corrosion through the life of the water heater.

Anode (Sacrificial)- A metal alloy electrode installed in the water heater cylinder that bygalvanic action protects the cylinder from corrosion.

Thermostat - A device responsive to temperature that controls the supply of electricalenergy to the compressor, which results in the stored water being maintained at therequired temperature.

Evaporator Thermistor - A device responsive to temperature that controls the active

supply between the compressor circuit and the booster element circuit.


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Compressor - An electro-mechanical device that adds heats to the refrigerant bycompressing it, known as heat of compression the resulting increase in refrigeranttemperature increases its pressure and causes the refrigerant to circulate through thesystem.

Evaporator - A finned copper coil mounted on top of the water heater. The refrigerantenters as a liquid, as it passes through the coil it absorbs heat from the surroundingatmosphere and boils off (evaporates) to a gas.

Condenser - An insulated housing containing stainless steel chambers where heattransfer occurs. The condenser (or heat exchanger) contains three chambers, one forrefrigerant, one for water and a third separating chamber containing air. The refrigerantenters as a gas, as it passes through the condenser it transfers (gives up) the heatabsorbed via the evaporator to the water flowing through the condenser in a separatechamber, during this process the refrigerant cools and changes state (condenses) back toa liquid.

Receiver Filter Drier- This device, fitted between the condenser and thermal expansion(TX) valve, receives and stores liquid refrigerant from the condenser for delivery to the

evaporator. The receiver also incorporates a filter and drier to trap impurities and removemoisture from the sealed refrigeration system

Accumulator- This device, fitted in the suction line prior to the compressor, is designed toaccumulate and prevent liquid refrigerant from entering and damaging the compressor.

Any liquid refrigerant is evaporated or boiled off and converted to a vapour by theaccumulator.

Thermal Expansion (TX) Valve - A valve, installed between the condenser andevaporator that controls (meters) the amount of refrigerant delivered to the evaporator.The TX valve has an external temperature sensor fitted to the suction line and increases ordecreases the refrigerant flow to the evaporator depending on the detected suction line

temperature.

Thermal Cut Out (Overload) - A manual reset temperature sensitive device thatautomatically cuts off the supply of electrical energy to the control board and/or boostelement.

Heating Unit (Element)- A tubular device containing an electric resistance element thatconverts electrical energy to heat. Standard element ratings are 2.4 and 3.6kW.

Common Faults

When a complaint is lodged about the performance of a hot water system there are anumber of causes that should be checked and eliminated. In an attempt to pinpoint themost likely cause it is important to discuss with the customer their reasons for thecomplaint, the duration of the problem, any change in circumstances or usage and recentweather conditions. This information in conjunction with the following listed commoncomplaints will assist you in locating the most likely cause. All procedures assume there iswater flowing through the water heater.

Discoloured water- This may be the result of discoloured water entering from the coldwater mains. Check if the cold water is also discoloured.

Excessive hot water usage- The complaints of insufficient hot water and no hot water

can on many occasions be attributed to hot water usage exceeding the capacity of thewater heater to provide hot water.


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When first attending a call of this nature it is essential to establish the probable hot waterusage by querying the usage habits of the household and compare this with the potentialdelivery of the model water heater installed. It can then be established if the usage iswithin or outside the capacity of the model. The areas to look at for excessive usage are:

1. Automatic washing machines.

2. Showers exceeding 12 litres/minute for mixed water and 5 minutes in duration.

3. Two or more showers operating at the same time.

4. Change of occupancy or number of persons increased.

5. High water pressure area. (Excessive pressure relief valve discharge)

6. Plumbing leaks.

7. Crossed connection.

Water hammer- A water heater will not cause water hammer, however valves associatedwith the water heater may be the source of the problem i.e. cold-water stopcock, non-return valve or relief valve.

Most water hammer problems are associated with plumbing, hot and cold or appliancesi.e. solenoid valves, ballcocks, loose pipes, sharp angles in pipe work, faulty or worn valveparts, loose tap washers or neighbouring equipment.

High water pressure areas will have more complaints of this nature and the use of apressure-limiting valve (PLV) to reduce the household cold-water pressure will usuallysolve most problems.

Hot water plumbing leaks- If hot water has not been used for a period of time, feelingthe temperature of the hot water line may give an indication of water flow if the pipe iswarm. The method of checking for plumbing leaks is:

1. Turn off the stopcock on the cold water supply to the water heater.

2. Open a hot tap to ensure the flow of water stops. This will confirm the stopcock isoperating correctly.

3. Turn off the hot tap.

4. Turn on the stopcock to make up the water pressure in the cylinder, and then turn thestopcock off again.

5. Wait approximately 5 minutes then do either of the following:

a. With your ear close to the stopcock turn it on slightly and listen for any waterpassing. If there are no leaks, water should not pass.

b. Open a hot tap while listening for any pressure release. If there is a pressurerelease there will be no leaks in the plumbing system.

Mixing or crossed connections - If an automatic dishwasher, washing machine, flickmixer tap, tempering valve or thermostatic mixing valve is installed there is always thepossibility that the cold water could mix with the hot water through a faulty or incorrectlyinstalled valve. This is referred to as a cross connection. The complaints of insufficient hotwater, water too cold or excessive discharge from the pressure relief valve may beattributed to a cross connection. The method of checking for a cross connection is:

1. Turn off the stopcock on the cold water supply to the water heater.

2. Open a hot tap. If water flow is persistent and cold a cross connection exists.


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Wiring Diagram


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12

Refrigeration Sealed System Diagram

LED Indication

All 310 series Heat Pumps have LED indication. There are two variations of LED indicationdepending upon the version of the controllers software; however all versions utilise a redand green LED to display the operational status and/or fault condition of the appliance.Note: The software version is printed on a label on the control board.

Controller Software Version HPV 3.1, HPV 3.2 or no HPV identification

310 Series Heat Pumps with controller version HPV3.1, HPV 3.2 or no HPV identificationhave a green and red LED located internally on the control board in the heat pump(refrigeration) module and utilise the following LED indication:

LED IndicationLED Status Condition Details

Green Solid S4 > 53C or S5 > 50CStandby mode (end of heating cycle,cylinder water at required temperature).

Green Flashing S4 < 44.5C or S3 < 50C Call for heat initiated.

Red FlashingVarious (refer to operatingsequence flow chart onpage 6 for more details).

Component fault or ambient conditionstoo cold for heat pump operation.

No indicationFault or system operatingin limp mode.

Fault or system in limp mode with call forheat satisfied (water in cylinder @ 70C

determined by mechanical thermostat).Note: Refer to diagram on page 5 for control board LED location.


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Controller Software Version HPV 4.0 or higher

310 series Heat Pumps with controller version HPV 4.0 or higherhave a red and greenLED located externally on the front of the heat pump module or internally on the controlboard in the heat pump (refrigeration) module depending upon date of manufacture.

LED Flashing Frequency:Different combinations of flashing red and/or green LEDs areutilised to indicate the operational status or fault condition of the Heat Pump. Each flash in

a series will last 0.5 seconds and is separated by 0.5 seconds between flashes. Eachseries of flashes is separated by 2 sec.

Example: LED provides 2 flashes: 1) LED on for 0.5 sec.2) LED off for 0.5 sec.3) LED on for 0.5 sec.4) LED off for 2 sec.5) Return to Step 1).

Operational LED Indication: If no fault is present the green LED will flash as shownbelow to indicate the operational sequence number the Heat Pump is currently operatingin (refer to operating sequence flow chart on page 6 for more details).

Operational LED Indication

Sequence Green LED Red LED0 Solid 0

2 2 flashes 03 3 flashes 0

4 4 flashes 0

Fault Indication:If a fault is present the green and/or red LEDs will indicate the faultcondition according to the table below.

Fault Indication

Fault Error Green LED Red LEDFaulty power supply or system in limp mode

with call for heat satisfied (1)N/A 0 0

T3 (comp dis) > 60C in sequence 0(2) SerrNo 4 1 Flash 0

T4 (ambient air) < 0C (3) SerrNo 1 0 Solid

Any Sensor Strip Sensor Fault Any Sflag 0 1 Flash

Water circ fault T0 (water outlet) > 80C SerrNo 2 0 2 Flashes

T2 (evaporator) < -3C SerrNo 8 0 3 Flashes

Comp/refrig fault T3 > T4 + 15C (in seq3) SerrNo 32 0 4 Flashes

Comp/refrig fault T0 - T1 < 8C (in seq4) SerrNo 32 0 5 Flashes

Water circ fault T1 > S4 + 7C SerrNo 64 0 6 Flashes

TRIAC/refrig fault T3 > 110C SerrNo 128 0 7 Flashes

Thermistor T0 Fault Tflag 1 1 Flash* 1 Flash*

Thermistor T1 Fault Tflag 2 2 Flashes* 2 Flashes*Thermistor T2 Fault Tflag 4 3 Flashes* 3 Flashes*Thermistor T3 Fault Tflag 8 4 Flashes* 4 Flashes*

Thermistor T4 Fault Tflag 16 5 Flashes* 5 Flashes*

Notes:* The green and red LEDs flash simultaneously in these cases.(1) System may be in limp mode with call for heat satisfied (water in cylinder @ 70C

determined by mechanical thermostat).(2) This condition creates a delay start for the compressor. This is not considered a fault.(3)Ambient temperature too cold for heat pump operation. This is not considered a fault.


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14

Fault Finding

Fault ChartNumber

Page

1 161.1 171.2 21

No Hot Water

7 43Insufficient hot water 2 23

3 243.1 25

3.2 253.3 263.4 27

3.5 293.6 303.7 30

8.1 44

Software versionHPV 3.1, HPV 3.2

or no HPVidentification

8.3 444 32

4.1 334.2 33

4.3 344.4 35

4.5 364.6 374.7 38

4.8 394.9 4.13 40

4.14 408 44

System in boost or limp mode

Software versionHPV 4.0 or higher

8.2 44Leaking water heater 5 41

Noisy water heater 6 42Blowing fuse/circuit breaker 7 43


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General Fault Finding Chart

Fault Diagnosis

No

hot water?YES 1

Insufficienthot water?

NO

2YES

System

in boost or limp

mode?

NO

3

YES

NO

5YES

6

NO

Leaking

water heater?

Noisy

water heater?

7

YES

NO

Blowing fuse/circuit breaker

Boost or limp mode will be

indicated by any of the followingLED conditions:

Red solid or flashing.

Red & green flashing together.

No LEDs (Limp mode with

Robertshaw thermostat open)

4

HPV 3.1, HPV 3.2 or

no HPV identification

HPV 4.0 or higher

What is the

controller

software

version?

Note: For more information on LED indication refer to pages 12 and 13.


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Fault Finding Chart 1

1

Warning: Terminals may be live.

Wear Personal Protecti ve

Equipment to prevent risk of

electric shock.Is 240

volts present at

the terminal

block? Test 1

1.1YES

Is

the heater

connected to an

off peak

tariff?

NO

Off peak connection is unsuitable for Heat

Pump models. Connect to continuous tariff or

off peak 2 if available

YES

Is the

isolating switch

or time clock

turned off?

NO

Restore power and advise customerYES

Is the

fuse blown at the

switchboard?

NO

Fault in household electrical wiringNO

Reset circuit breaker

or rewire fuse

YES

Did

the fuse or

circuit breaker blow

again?

7YES

1. Heat pump connected to mixed circuit,

possible excessive current draw or another

appliance with a fault

2. Faulty circuit breaker or fatigued fuse wire

3. Unit may be short cycling due to faultythermostat

NO

No Hot Water


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Fault Finding Chart 1.1

Note: Ensure you

wait the full five

minutes before

progressing from

this point.

1.1

Are the

thermostat contacts

closed?

NO Replace thermostat.

Test 2

No Hot Water

Is there

240V at the

control board &

relay?

Test 3 Wiring incorrect.

Check control board wiring loom

plug (lower thermostat to control

board wiring loom).

NO

Test 4

What is the

status of the

control boards

LEDs five

minutes after

resetting?

Replace control board.

Red solid or Red and

Green LEDs indicatingsimultaneously

Green flashing

Green solid

No indication

1.2

Replace sensor strip.

Replace control board (system

should have been operating in

boost mode after five minutes

from resetting) then check

system operation as a second

fault may be present.

YES

Note: To reset heat

pump switch power off,

wait for 30 seconds

then switch back on.

Reset heat pump &

wait five minutes

before progressing

from this point.

Is the

compressor

running?

Is the

sensor strip

working?

NO

YES

Is the

refrigeration

system

heating?

YES

NO

YES

NO

To check if the refrigeration system is

heating feel the braided flexible hose

from the heat exchanger water outlet.

What is the

controller

software

version? HPV 3.1, HPV 3.2 or


HPV 4.0 or higher

Is

sensor T3

working?

YES

Replace sensor T3.NO

Test 5

System working ok. The element circuit should be

checked as a temporary condition may have caused the

appliance to enter boost mode. If in boost mode and the

element circuit is not operational the cylinder water will

be cold and the system cannot reset itself automatically.


YES

Is the

evaporator fan

operating?

YES

3.6NO

1.2Red flashing

Is

the air flow

obstructed?

NO

Remove obstruction or clean

evaporator.YES

Note: For more information on LED indication refer to pages 12 and13.


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Component Tests 1, 2, 3 & 6

Tests 1 Test 2

240

Warning Live equipment wearPersonal Protective Equipmentwhen conducting th is test.

Using a multimeter on the AC voltagescale, measure between the terminals ofthe terminal block located behind theelement access cover. The followingmeasurements should be obtained:

Active & Neutral 240 volts.Active & Earth 240 volts.Neutral & Earth 0 volts.

Warning - Ensure power isisolated before conducting thistest.

Using a multimeter on the ohms scale,measure between the terminals of themechanical thermostat. The followingresults should be obtained:

1L & 2T 0 ohms.3L & 4L 0 ohms.

Test 3 Test 6

240

240

Warning Live equipment wearPersonal Protective Equipmentwhen conducting this test.

Using a multimeter on the AC voltagescale, measure between the top 2 terminalsof the heat pump module terminal block.

Normal voltage is 240 volts.

Warning Live equipment wearPersonal Protective Equipmentwhen conducting th is test.

Using a multimeter on the AC voltagescale, measure between the A return andNeutral terminals of the terminal blocklocated behind the element access cover.


Note:Refer to page 19 for component test 4 and page 20 for component test 5.


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8.49

Component Test 4

Warning Live equipment wear Personal Protective Equipment whenconducting this test.

Sensor Strip Testing:Unplug the sensor strip plug from the control board and using amultimeter on the kilo-ohms scale, measure between the pins of the sensor strip plug*.There are six individual tests to be performed as there are six individual sensors contained

along the length of the sensor strip (sensors S0 S5). As the resistance of each sensorwill change according to its temperature, the resistance measurements for each sensor willneed to be checked against the Temperature/Resistance Table shown below. For thisreason it is best to empty the tank of hot water and then measure the cold watertemperature at the T&PR so a known temperature datum can then be applied to allsensors which should then in turn all have similar resistance value when tested.

Sensor Test Points

S0 Between Pins 1 and 9






*Note: The sensor strip plug socket test points are quite small, Fine Probe Adapters (partnumber WH0020082) can be utilised as probe extensions. Alternatively small pins may beused however ensure good contact is made when testing.

Sensor Strip Temperature / Resistance Table

T (C) R (k) T (C) R (k) T (C) R (k) T (C) R (k) T (C) R (k)-10 37.45 10 15.45 30 7.037 50 3.485 70 1.853

-9 35.73 11 14.82 31 6.782 51 3.371 71 1.799-8 34.11 12 14.22 32 6.537 52 3.262 72 1.743

-7 32.56 13 13.65 33 6.302 53 3.157 73 1.695-6 31.10 14 13.10 34 6.076 54 3.055 74 1.646

-5 29.71 15 12.58 35 5.86 55 2.957 75 1.589-4 28.39 16 12.09 36 5.653 56 2.863 76 1.552

-3 27.13 17 11.61 37 5.454 57 2.773 77 1.508-2 25.94 18 11.16 38 5.264 58 2.686 78 1.465-1 24.81 19 10.72 39 5.081 59 2.602 79 1.424

0 23.73 20 10.31 40 4.905 60 2.521 80 1.3841 22.71 21 9.913 41 4.736 61 2.442 81 1.3452 21.73 22 9.535 42 4.574 62 2.367 82 1.3073 20.81 23 9.173 43 4.418 63 2.295 83 1.271

4 19.92 24 8.826 44 4.269 64 2.225 84 1.2365 19.09 25 8.495 45 4.125 65 2.157 85 1.202

6 18.29 26 8.177 46 3.987 66 2.092 86 1.1697 17.52 27 7.873 47 3.854 67 2.029 87 1.1378 16.80 28 7.583 48 3.726 68 1.968 88 1.107

9 16.11 29 7.304 49 3.603 69 1.91 89 1.077

Sensor strip plugpin configuration

Testing thesensor strip


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20

Component test 5

T Sensor Testing:310 Series Heat Pumps have five independent thermistors which areutilised to monitor temperatures at various locations around the system. These thermistorsconnect to and are monitored by the control board and are known as T sensors.

All five T sensors are identical and each can be tested as follows:

Warning - Ensure power is isolated before conducting this test.

Unplug the relevant T sensor from thecontrol board and remove the T sensorfrom its location so its temperature will bethe same as the ambient air temperature(As sensor T4 detects the ambient airtemperature it may remain in position forthis test). Using a multimeter on the kilo-ohms scale, measure between the two pins

of the T sensor plug*. As the resistance ofeach sensor will change according to itstemperature, the resistance measurementsfor each sensor will need to be checkedagainst the Temperature/Resistance Tableshown below and the value then comparedto the ambient air temperature.

*Note: The sensor strip plug socket test points are quite small, Fine Probe Adapters (partnumber WH0020082) can be utilised as probe extensions. Alternatively small pins may beused however ensure good contact is made when testing.

Sensor Monitors Part NumberT0 Water temperature leaving the condenserT1 Water temperature entering the condenser

T2 Evaporator temperatureT3 Compressor discharge temperatureT4 Ambient air temperature

056006

T Sensor Temperature / Resistance Table

The table below sets out the resistance of the T sensors for a given water or air

temperature.

TemperatureDegrees C

Resistance (All T Sensors)Kilo-ohms

0 23.7310 15.4520 10.31

30 7.03740 4.90550 3.485

60 2.521

70 1.85380 1.384


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21

Fault Finding - Chart 1.2

1.2

Is there

240V at the

element?

NO

Test 6

No Hot Water

Test 8

YES

YES

Is there

240V at the N/C

relay contact?

YES

Is there

6VDC at the relaycoil?

NO

YES

NO

Is the

element resistancecorrect?

NO

Test 7

Test 9

Repair faulty wiring.Appliance operation should then

be checked to determine why thesystem entered boost or limp

mode as a second fault may bepresent.

Replace element.Appliance operation should then

be checked to determine why thesystem entered boost or limp


Replace relay.

Appliance operation should thenbe checked to determine why thesystem entered boost or limp

mode as a second fault may be

present.


Appliance operation should thenbe checked to determine why the

system entered boost or limpmode as a second fault may be

present.

Repair faulty wiring between heatpump module electrical

connection plug and element.Appliance operation should thenbe checked to determine why the

system entered boost or limp


Note: all faults in this chart are in the boost or limp mode (element)

circuit. After determining the fault in the element circuit the applianceoperation should then be checked to determine why the system

entered boost or limp mode as a second fault may be present.


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22

Component Tests 7, 8 & 9

Tests 7 Test 8

240

Warning Live equipment wearPersonal Protective Equipment

when conducting this test.Using a multimeter on the AC voltagescale, measure between the white wire onthe heat pump module electricalconnection plug and the top terminal of theheat pump module terminal block(Neutral).


Warning - Ensure power isisolated before conducting this

test.Disconnect the element wires from thethermostat and terminal block, and using amultimeter on the ohms scale, measurebetween the two element wires. Thefollowing results should be obtained:

2.4kW element: 22 26 ohms.3.6kW element: 15 17 ohms.

Test 9

Warning Live equipment wear Personal Protective Equipment whenconducting this test.

Using a multimeter on the DC voltage scale, measure between the two wires on thecontrol board relay plug.

Normal voltage is 6 Volts DC.


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23

Fault Finding - Chart 2

2

YESRecommend a water heater ofsufficient capacity to meet the

customers needs.

Insufficient Hot Water

NO

Has the

supply of hot water

recently been

depleted?

Boost or limp mode may beindicated by any of the following

LED conditions:Red solid or flashing.

Red & green flashing together.

No LED indication.Has the

usage pattern

changed

recently? i.e. additional appliances

or people using hot water

Depending on the ambient

temperature the water heater may

take 3 to 5 hours to recover.

Is theheater of sufficient

size?

NO

Recommend a hot water usage

pattern that will suit the water

heater and the customers needs.

YES

Is the

water supply pressuremore than 80% of the

T&PR rating?

Fit pressure limiting valve if not

already installed.

Existing pressure limiting valve

faulty - replace.

YESYES

Is thecorrect T&PR

valve fitted?

NO

NO

YES

Check for crossed water

connection.

Replace T&PR valve.

Replace T&PR valve with one ofcorrect pressure rating.

Do not use reconditioned T&PR

valves.

Are there

any plumbing leaks,

crossed connections or

dripping taps?

NO

Repair any leaks.

Isolate crossed connections.

YES

Is theheater operating

in boost or limp

mode?

NO

What is the

controller

software

version?

YES

3

4

HPV 3.1, HPV 3.2 or


HPV 4.0 or higher

Is the

T&PR valve

continuously

discharging

water?

YES

NO

Is theheater outlet water

temperature> 58C

Is atempering valve

fitted?

Arethe filtersblocked?

NO

Clean or replace filtersYES YES

Is thetempering valve outlet

water temperatureapprox 48C?

NO

NO

Replace tempering valveNO

YES

System workingYES

NO

Is the

sensor strip

working?

NO

YES

Replace sensor strip

Test 4

The heater outletwater temperature

can be measured at

the T&PR.

Is the heater

connected to anoff peak tariff?NO

Off peak connection is unsuitablefor Heat Pump models. Connect

to continuous tariff or off peak 2 ifavailable.

YES

Note: This assumes thatthe hot water to the

tempering valve is above52C.

Note: For more information on LED indication refer to pages 12 and 13.


25/68



24

Fault Finding - Chart 3

3

System in boost or limp mode - Software version HPV 3.1, HPV 3.2 or no HPV

identification

What is the

status of thecontrol boards

LEDs?


Red solid or Red and Green LEDs

indicating simultaneously

Red flashing

Green solid

Green flashing

Test 4

System working. Check operation.

No LED Indication 3.1

NO

YES NO

Are therelay, circulator,

fan, sensor strip & Tsensors all firmly plugged

into the correctsockets?

YES

Ensure plugs are firmly plugged

into correct sockets on control

board and that plug pins on

control board are clean and free

from conformal coating.

NO

Test 5

Is the

sensor stripworking?


Are all

T sensors

working?

Replace faulty T sensor(s).

Ensure water in heatpump is below 60C&

reset heat pump. Toreset heat pump switchoff, wait for 30 seconds


Does

compressor

successfully start

after delay?

Note: The compressor

starts 30 seconds after

the circulator.

NO

NO

Is

circulatoroperating?

Does

compressor try

to start after

delay?

NO

3.3

3.4

Circulator operation can be

checked by feeling circulator

brass body for vibration.

Let heat pumprun for ten

minutes or untilred LED flashes.

Does

red LED

flash?

YES

Red LED will flash if

system enters boost

mode.

8.3

Has

compressor

recently beenoperating?

YES

Compressor internal OTCmay have opened.

Switch off power to heatpump, wait for ten

minutes then switchpower back on.

YES

NO

3.5YES

System working. Ambient air

temperature may have been too high or

low for normal operation. Heat pump

may have been too hot after operating

for an extended period due to large

volumes and/or frequent water usage.

NO

YES

YES

LED

Status

after5

seconds

Green - flashing

Red solid or flashing / Red and Green

indicating simultaneously / Green solidReplace control board.

3.2Red - flashing

3.8

Note: Refer to page 5 for T sensor plug socket location on control board.


26/68



25


3.1

Are the

thermostat contactsclosed?

YESRepair faulty wiring.


Test 2


identification

NO

System has operated in limp mode

due to a faulty sensor strip (S1 & S4

faults) and has completed a heatingcycle. Water was heated by the

electric element and controlled bythe Robertshaw thermostat to 70C.


Is the

sensor strip

working?

NO


YES

Test 4

Are thesensor strip plug

pins clean?

Ensure sensor strip plug pins andcontrol board socket are clean

and free from conformal coating.

NO

YES


3.2

T0 is monitoring

water out of the

heat exchanger

Switch off heat pump &allow sensor T0 to cool

below 80C. Whensufficiently cool switchheat pump back on.

Is redLED flashing after

5 seconds?

Replace control board

YES

Is

Green LEDflashing?

NO

YES

Circulator operation can bechecked by feeling circulator

brass body for vibration.

NO

Hassensor T0 cooled

to below80C?

YES

NO

Is circulator

operating?3.3NO

3.8YES



identification


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26


3.3

Ensure circulator is firmly plugged

into correct socket on control




NO

YES

Is the

circulator motor

resistance

correct?

Is 240V

present at the

circulator?

Test 10 Is the

circulator plug firmly

plugged into correctsocket?

NO

Check circulator impellor for

restriction or siezure.

YES

Replace circulator

YES

NO

Test 11



identification

Component Tests 10 & 11

Test 10 Test 11

Warning Live equipment wear

Personal Protective Equipmentwhen conducting this test.

Using a multimeter on the AC voltagescale, measure between the circulatorplug terminals at the control board.


Note: As the control board controls thespeed of the circulator by pulsing theelectrical supply to the circulator ananalogue multimeter may indicatebetween 180 240V.

Warning - Ensure power is

isolated before conducting thistest.

Unplug the circulator connection plug fromthe control board and using a multimeter onthe ohms scale, measure between the twocirculator connection plug terminals.

A reading of approximately 75.3 ohmsshould be obtained.


28/68



27


3.4

Is 240V

present at the

compressor

terminals?

NO Faulty compressor wiring.

YES

Are

the compressor

winding resistances

correct?

Test 12

Replace compressor

NO

Faulty compressor and/orcompressor capacitor wiring.

YES

Note: Tests 12 & 13 must be

performed after waiting for the 30second delay after starting of the

circulator and cannot be performed

whilst the red LED is flashing.

Test 14

Is the

compressor

capacitor

working?

Replace compressor capacitorNO

YES

Is 240V

present at the control

board compressor

terminals?

YES

Test 15

Test 13

Replace control boardNO

Is there

6VDC at the relay

coil?

Is the

relay plug pluggedinto the control

board?

NO

YES

Plug in relay plug at control board.NO

Ensure plug pins are clean of

conformal coating and are making

contact. If plug & pins are ok

replace the control board.

YES

Test 9


identification

Are

the compressor

winding resistancescorrect?

Compressor internal ECOmay have tripped open

circuiting the compressor

windings. Wait ten

minutes for ECO to cool

and auto reset.

NO

Is the

compressortemperature 150C

or hotter?

Reset heat pump and run

system until compressor

ECO trips again.

YES

Test 14

8.3YES

NO

Note: To reset heat

pump switch power off,

wait for 30 seconds


Note: Compressor internalECO is auto trip & auto

reset & is not a replaceable

component.

ECO Opens @ 150C

ECO Closes @ 90C


29/68



28

Component Tests 12 15

Tests 12 Test 13


when conducting th is test.

Remove the compressor electrical accesscover and using a multimeter on the ACvoltage scale, measure between the redand blue wires.



when conducting this test.

Using a multimeter on the AC voltagescale, measure between the control boardcompressor output terminal and the topterminal of the heat pump module terminalblock (Neutral).


Test 14 Test 15


Remove the compressor electrical accesscover and mark and disconnect terminalwiring. Using a multimeter on the ohmsscale, measure between the compressorterminals. The following run and startwinding results should be obtained.

(Run) Red & Blue terminals 2.2 ohms(Start) Red & Black terminals 3.2 ohms


Disconnect the wiring to the compressorcapacitor and using a multimeter on thecapacitance (F) scale measure betweenthe two capacitor terminals.

Normal capacitance is 35 micro Farads(35F).


30/68



29


3.5

Is the

temperature atsensor T4< 2C?

System functioning correctly andshould operate in boost mode

until temperature at T4 risesabove 2C at which time the heat

pump will reset and start back at

sequence 0.

YES

T4 is ambientair sensor

Is thetemperature at

sensor T2< 2C?

NO

3.6YES

T2 is evaporator

sensor Is theambient air

temperature 60C in seq 0)Green 2 flash - Heat pump operating in sequence 2

Green 3 flash - Heat pump operating in sequence 3

Green 4 flash - Heat pump operating in sequence 4

Other LED indication:If no fault is present the Green LED

will flash to indicate the following:

4.1Red solidRed solid or flashing.

Red & Green flashing simultaneously.

No LED indication.

For other LED indication refer to notes

below.

For more information on LED indication refer to pages 12 and13.


34/68



33


4.1

Is

sensor T4firmly plugged

into correctsocket?

NO

Ensure sensor T4 is firmly

plugged into correct socket oncontrol board and that plug pins

on control board are clean andfree from conformal coating.

Red solid

T4 < 0C

YES

Is thetemperature atsensor T4

< 2C?

NO

YES

Issensor T4

working?

Test 5

Replace sensor T4NO

Replace control boardYES

T4 is ambient

air sensor

Note: When T4 < -0C the system will enter boost mode. When in boost mode dueto this operation the system will reset and start at sequence 0 when T4 > 2C

System functioning correctly and

should operate in boost modeuntil temperature at T4 rises

above 2C at which time the heatpump will reset and start back at

sequence 0.



4.2

Is thesensor strip

working?

NO

Red 1 flash

sensor strip fault

Is thesensor strip

firmly pluggedinto the correct

socket?

YES

NO

Test 4


Ensure sensor strip is firmly

plugged into correct socket oncontrol board and that plug pinson control board are clean and

free from conformal coating.

Replace sensor strip


35/68



34


4.3

NO

Red 2 flashT0 >80C

YES

YES

NO

Test 5

T0 is monitoring

water out of the

heat exchangerIs

sensor T0

firmly pluggedinto correct

socket?

Is

sensor T0

working?

Replace sensor T0



Does red

LED immediately

go to 2 flash?


YES

Is circulator

operating?

NO

Blockage of water system atcirculator, heat exchanger,

dropper tubes or flexible hoses.

Loose, damaged or jammed

circulator impellor.

YES

Circulator operation can be

checked by feeling circulatorbrass body for vibration.

NO

Ensure circulator is firmly pluggedinto correct socket on control




NO

YES

Is the

circulator motor

resistance

correct?

Is 240V

present at the

circulator?

Test 10 Is the

circulator plug firmly

plugged into correct

socket?

NO

Check for loose, damaged or

jammed circulator impellor.

YES

Replace circulator

YES

NO

Test 11

Hassensor T0 cooled

to below80C?

YES

NO



plugged into correct socket on

control board and that plug pinson control board are clean and


Is there

an air lock in the

water system?

NO

Bleed air from water outlet at

flexible hose union.YES

Warning! Ensure water escaping

from flexible hose is caught in a

container and does not escape or

sensor strip damage may occur.



36/68



35


4.4

Is


into correctsocket?

NO


plugged into correct socket oncontrol board and that plug pins

on control board are clean andfree from conformal coating.

Red 3 flash

T2 < -3C

Is thetemperature atsensor T2

< 2C?

NO

Issensor T2

working?

Test 5

Replace sensor T2NO


T2 is evaporatorsensor

System functioning correctly andshould operate in boost mode

until evaporator temperature rises

above 2C at which time the heatpump will reset and start back at

sequence 0.

Did the

system reset &operate in normal

heat pumpmode?

Is theambient air

temperature 2C

Is

the air flowobstructed?

NO

Remove obstruction.YES

YES

Clean dirty evaporator.

Appliance installed in enclosedroom contrary to installation

instructions. Appliance is suitablefor outdoor installation only.

Raise temperature of sensor T2 to

above 2C by removing fromevaporator and holding probe between

thumb & fingers. Heat pump shouldauto reset to sequence 0 when T2raises above 2C. Ensure sensor

probe is reinserted into evaporator on

completion of testing procedure.



37/68



36


4.5

Is 240V

present at the

compressor

terminals?


Red 4 flash

T3 is not > T4 +

15C in sequence 3

YES

Does

compressor start

or try to start after

delay?

YES

Are

the compressor

winding resistances

correct?

Test 12

Replace compressorNO

Faulty compressor and/or

compressor capacitor wiring.

YES

Note: T3 is compressor discharge sensor. T4 is ambient air sensor. This check is performed in sequence 3 to

ensure that the sealed refrigerant system is operating (heating).

8

Are

sensors T3 & T4

firmly plugged into

the correct

sockets?

Ensure sensors T3 & T4 are firmly

plugged into correct sockets on

control board and that plug pins

on control board are clean and


NO


performed after waiting for the 30

second delay after starting of the



Test 14

NO

Is the

compressor

capacitor

working?


Note: The compressor starts 30

seconds after the circulator.

YES

Are

sensors T3 & T4

working?

Replace faulty sensor(s)NO

Ensure water in heatpump is below 60C &reset heat pump. Toreset heat pump switch

off, wait for 30 secondsthen switch back on.

YES

Does red

LED immediately

go to 4 flash?

NO

YES

Is 240V


board compressor

terminals?

YES

Test 15

Test 13

Test 5



Is there

6VDC at the relay

coil?

Is the

relay plug plugged

in to the control

board?

NO

YES

Plug in relay plug at control board.NO

Ensure plug pins are clean of

conformal coating and are makingcontact. If plug & pins are ok

replace the control board.

YES

Test 9

YES



38/68



37


4.6

Is 240V

present at the

compressor

terminals?


YES

Does

compressor start

or try to start after

delay?

NO

YES

Are

the compressor

winding resistancescorrect?

Test 12

Replace compressorNO

Faulty compressor and/or

compressor capacitor wiring.

YES

8

Are

sensors T0 & T1

firmly plugged into

the correct

sockets?

Ensure sensors T0 & T1 are

plugged into correct sockets on

control board and that plug pins



NO


performed after waiting for the 30

second delay after starting of the



Test 14

Is the

compressor

capacitor

working?


Note: The

compressor starts 30

seconds after the

circulator.

YES

Are

sensors T0 & T1

working?

YES

Replace faulty sensor(s)NO

Ensure water in heatpump is below 60C &reset heat pump. Toreset heat pump switch

off, wait for 30 secondsthen switch back on.

YES

Does red

LED immediately

go to 5 flash?

NO

YES

Is 240V


board compressor

terminals?

YES

Test 15

Test 13

Test 5



Red 5 flashT0 - T1 < 8Cin

sequence 4

Note: T0 is heat exchanger water outlet sensor. T1

is heat exchanger water inlet sensor. This check is

performed in sequence 4 to ensure that the sealed

refrigerant system is operating (heating).



39/68



38


4.7

Is thesensor strip & sensor

T1 firmly plugged intothe correct

sockets?

Ensure sensor strip & sensor T1

are both firmly plugged into the

correct sockets on control boardand that plug pins on control

board are clean and free from

conformal coating.

NO

YES

Is

sensor T1working?

Replace sensor T1NO

YES

Test 5

Replace cold water dropper tube.

Red 6 flashT1 > S4 + 7Cinsequence 3 or 4

Note: T1 is heat exchanger water inlet sensor. S4 is thermistor sensor strip sensor.

This check is performed in sequence 3 or 4 to ensure that the circulator is operating.

Is

sensor stripworking?

YES

Replace sensor stripNO

Is thecirculator water

flow directioncorrect?

YES

NOReinstall circulator so as flow is

directed towards heat exchanger.

Has thecold water dropper

tube fallen off?

YES

Replace control board.NO

Test 4

Is there

an air lock

in the watersystem?

Bleed air from water system at

water outlet flexible hose union.YES

NO

Warning! Ensure water escaping

from flexible hose is caught in a

container and does not escape or

sensor strip damage may occur.



40/68



39


4.8

NO

YES

System working ok. Ambient air

temperature too hot for normal

heat pump operation.

YES

Test 5

Appliance may have been

operating for an extended period

due to large volume and/or

frequent water usage.

Red 7 flashT3 > 110Cin

sequence 3 or 4

Note: T3 is compressor

discharge sensor.

NO

YES

Is


into correct

socket?

YES

NO

NO

Test 19


plugged into the correct socket oncontrol board and that plug pins



Replace sensor T3

Is

sensor T3

working?

Isthe ambient air

temperature above50C?

8.2

Fit pressure gauge to

high side of

refrigerant system

Is the

head pressure

excessive?

Hassensor T3 cooled

to below60C?



NO

YES



41/68



40

Fault Finding Charts 4.9 to 4.13

4.9

NO

T sensor fault

YES

NO

Test 5

Is

T sensorfirmly plugged

into correct

socket?

Replace T sensor.

Ensure T sensor is firmly plugged

into correct socket on controlboard and that plug pins on



4.10 4.11 4.12 4.13


IsT sensor

working?

T0 fault.

T0 is monitoringwater out of the

heat exchanger.

T1 fault.

T1 is monitoringwater into the

heat exchanger.

T2 fault.

T2 is monitoringthe evaporator

temperature.

T3 fault.

T3 is monitoringthe compressor

discharge temp.

T4 fault.

T4 is monitoringthe ambient air

temperature.

YES



4.14

Are the

thermostat contactsclosed?

YESRepair faulty wiring.


Test 2

System in boost or limp mode - Software version 4.0 or higher

NO

System has operated in limp modedue to a faulty sensor strip (S1 & S4

faults) and has completed a heatingcycle. Water was heated by the

electric element and controlled by

the Robertshaw thermostat to 70C.

Replace sensor strip.Is the

sensor strip

working?

NO


YES

Test 4

Are thesensor strip plug

pins clean?

Ensure sensor strip plug pins andcontrol board socket are clean

and free from conformal coating.

NO

YES

Is there

240V at thecontrol board &

relay?

YES

Wiring incorrect.

Check control board wiring loomplug (lower thermostat to control

board wiring loom).

NO

Test 3


42/68



41


5

Isthe T&PR

valve continuouslydischarging

water?

Existing pressure limiting valve

faulty.Fit pressure limiting valve if not

already fitted.

Replace T&PR valve if required.

Is theleak from the

electrical accesscover?

NO

YES

NO

Is theleak from

the element barrelfitting?

YESCheck for loose element bolts.Remove element and replace

gasket.

YES

NO

Remove anode and repair leakusing Teflon thread tape.YES

Is the

correct T&PR valvefitted?

Replace T&PR valve with one ofthe correct pressure rating.

Do NOT use reconditioned

T&PR valves.

NO

Check for crossed waterconnection.

Replace T&PR valve.

YES

Is thewater supply

pressure above800kPa?

YES

NO

Isthe water leak

intermittent?

NO

Leak is probably condensatedraining from the evaporatorcondensate tray.

Normal Operation.

YES

Arethe anode/s

leaking?

Inner Cylinder leakingCheck for hot spots on the jacket

Replace water heater.

NO

Isthe leak from theheat pump water

system?

NO

Tighten or remake flexible hose

connection(s).

Repair or replace leaking heatexchanger.

Replace leaking circulator.

Remake or replace dropper tubeconnections.

YES

Leaking water heater


43/68



42


6

Fan loose on motor shaft, remove

assembly and tighten.Fan motor faulty - Replace.

Is the

noise water

hammer?

NO

NO

Is thenoise only evident

when water is flowing

through the

heater?

YES

Cylinder contracting due to pressure

release when hot tap opened.

This can also be accompanied by a

creaking or cracking sound.

Normal Operation.

NO

Check for restrictions in pipe work, faulty

valves, loose plumbing or other

appliances i.e. washing machine or

dishwasher.

Fit 600kPa pressure limiting valve.

YES

Is

the noise

mechanical or air

related?

Normal noise level during operation is

approximately 52dB at 1.5 metres.

If this level is affecting neighbors a timer

should be fitted to prevent operation

during the affected hours or to comply

with local council regulations

AIR

Is the

noise from the

evaporator

fan?

Is the

noise only evident

during the heating

cycle?

Check for loose fittings or pipe work in

the refrigeration system.

Check for possible mechanical failure in

compressor

YES

Is the

water pressuremore than 80% of the

T&PR valve

rating?

Check all other appliances or valves that

can generate noise i.e. washing

machines, dishwashers, ball valves etc.

NO

YES

Mechanical

Refer to water hammer causes in the

Common Complaints section.

Check for a faulty stop cock, non-return

valve or T&PR valve.NO

Is the

noise a

metallic popping

sound?

YES

NO

YES

Noisy water heater


44/68


45/68



44

Fault Finding Chart 8 - 8.3

8.3

Replace compressor.

Test 19

Refrigeration system fault finding

Is the

head pressure

excessive?

Test 21

NO

Fit pressure gauge

to high side of

refrigerant system.

Allow time for the

system to equalise.

Did

the system

equalise?

Is the system

taking too long to

equalise?

Possible restriction in system,

Locate and repair.

Possible system overcharge,

adjust refrigerant charge.

TX valve metering incorrectly,

adjust or replace TX valve.

NO

YES

Is theTX valve

operating?

NO

Locate blockage in refrigerant

system and repair.

YES

Adjust TX valve (refer to

component replacement

procedure 23 TX valve

adjustment) or replace if faulty.

NO

System overcharged, adjust

refrigerant charge.YES

YES

8.28

Fit pressure gauges

to high and low side

of refrigerant system.

Is the

Suction pressure

low/vacuum or

excessively

high?

Test 20Locate and repair leak in

refrigerant system.

High side head pressure excessive (Test 18)

YES

High

Low

NO

8.1


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Component Test 19

Warning Live equipment. Wear Personal Protective Equipment whenconducting this test.

1800 kPa

Fit gauges to the high side access pipeand observe the discharge pressure.

Typical high pressure range is 1400-2100 kPa depending on cylinder watertemperature. The high pressure rangeshould be within 1700-1800 kPa whenheating from cold.

Component Test 20


400 kPa

Check for persistent air bubbles throughsight glass of receiver/filter drier. Fitgauges to the low side access pipe and

observe the suction pressure.

The suction (low side) pressure is verydependent on ambient conditionshowever the low pressure range istypically between 200-600 kPa.

200 kPa @ 10C ambient.600 kPa @ 45C ambient.

A suction pressure of less than 200kPamay indicate a refrigerant leak or a

malfunctioning TX valve.

Note: Refer to the following section formore information on refrigerant chargeand refrigerant charge fault indications.

Refrigerant Charge

Indication of correct refrigerant chargeThe receiver/filter dryer sight glass should show clear liquid, a few small bubbles might bevisible during initial start up of the system or when the TX valve opens quickly, howeverclear liquid should return shortly after. Compressor current draw should be between 5 6

Amps and system pressures should be within normal ranges (refer to component test 19(above) and component test 20 (above) for typical system pressures).


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Indication of undercharged systemBubbles persist for a significant amount of time or repeat often. Compressor current drawis low (6 Amps) and compressor noisy. Note:Unusual currentdraw or high head pressure can be a sign of other problems such as a blockage ormalfunctioning TX valve.

Component Test 21


Fit gauges to low side access pipe.

Remove the insulation from the TX valvesensor on the suction line.

Hold the sensor by hand to increase theheat detected by the sensor. The TXvalve should open with the followingresults:

1. Flow of refrigerant through sight glassof receiver/filter dryer should increase.

2. Evaporator pressure should increase.3. Suction line should become cooler.

Remove hand and replace insulation, theTX valve should close, resulting in thereversal of the above results.

Electrical Insulation Testing

There are three basic test procedures that should be carried out when the operation andfunction of a heat pump water heaters electrical system is in doubt.

Wear Personal Protective Equipment when conducting step 1 of thisprocedure to reduce the risk of electric shock. Refer to Rheem safety

procedure on electrical testing.Insulation resistance of the water heater Neutral Circuit. (Reading not to be below0.66 Mega ohm).

1. Isolate power to the water heater at the isolation swi tch. Confirm with multi-meter across terminal block Active and Neutral, then Active and Earth , thenNeutral and Earth that vol tage is not present.

2. Once satisfied, disconnect the Active and Neutral wires from the water heater terminalblock.

3. Connect megger leads to the Neutral of the water heater wiring and Earth.

4. Operate megger. A reading above 0.66 Mega ohm should be obtained.

5. If a reading below 0.66 Mega ohm is indicated, all component parts will need to beindividually tested to locate the fault. Refer to Fault Finding Chart 7 on page 43.


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Insulation resistance of the water heater Active Circuit (reading not to be below 0.66mega-ohm).

6. Connect megger leads to the Active of the water heater wiring and Earth.

7. Operate megger. A reading above 0.66 Mega ohm should be obtained.

8. If a reading below 0.66 Mega ohm is indicated, all component parts will need to be

individually tested to locate the fault. Refer to Fault Finding Chart 7 on page 43.

To check Continuity of the Heat Pump electrical circuit.

9. Set megger to resistance scale or multimeter to x1 resistance scale.

10. Measure between the Active and Neutral terminals on the power supply terminal blocklocated behind the electrical/element access cover. The resistance should beapproximately 24 ohms. If a reading outside this resistance is measured all electricalcomponent parts will need to be individually tested to locate the fault. Refer toSpecifications table on page 3 for indicative resistance values of components.

11. Reconnect active cable

tm025 rheem 310 series heat pump rev b.pdf

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