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Heat Pump Water Heater  

19 

T h e r m i s t o r s   ( a m b i e n t ,   s u c t i o n ,   d i s c h a r g e ,   w a t e r   o u t ,   e v a p o r a t o r ,  
u p p e r   t a n k   a n d   l o w e r   t a n k )  

There are seven (7) thermistors on the HPWH. Each one uses a standard 10,000 ohms resistor. 
By measuring the resistance of the thermistor from the control board, you can determine if the 
thermistor is working properly. 
 
See chart for resistance values of the thermistors. They are all 10,000 ohm 
based thermistors, so this chart will work for any of the thermistors on the 
HPWH. 

1.

 

Turn the power off to the HPWH. You will expose yourself to a 
potential shock when you reach for a thermistor. 

2.

 

Open the upper cover that surrounds the heat pump portion of the 
water heater. 

3.

 

Locate the circuit board 

4.

 

Locate the specific thermistor you want to test. 

5.

 

Remove the thermistor from the circuit board. 

6.

 

Measure ohms resistance between the two wires of the thermistor. 

7.

 

Compare this resistance to the chart on the last page and determine 
the temperature. 

Figure 9 – Thermistor Connections 

 

F a n   A s s e m b l y  

1.

 

Cycle the water heater to Energy Saver or Normal mode. The fan does not work in 
electric heat only mode. 

2.

 

You should hear the fan running.  

3.

 

Locate the fan motor Molex on the circuit 
board. 

4.

 

Measure for 240 volts AC between the 
black and blue wires.  

5.

 

If you have voltage, and the fan is not 
running, replace the fan. If you do not have 
voltage, replace the circuit board. 

Figure 10– Fan Motor and Water Pump Connections 

 

W a t e r   P u m p  

1.

 

Cycle to water heater to Energy Saver or Normal mode. The water pump works in all 
operating modes mode. 

2.

 

You may hear the pump running or feel the pump vibrate.  

3.

 

Locate the water pump Molex on the circuit board. 

4.

 

Measure for @160 – 240 volts AC between the black and blue wires.  

5.

 

If you have voltage, replace the water pump. If you do not have voltage, replace the 
circuit board. 

 

Содержание RUUD Iraining

Страница 1: ......

Страница 2: ...IONS OF THE CONTROLS 16 ECO Energy Cut Off 16 Power Outages 16 Heat Pump and Compressor Operations 16 TROUBLESHOOTING 16 Error Code LED Light 16 Troubleshooting the Heat Pump Components 17 TROUBLESHOOTING COMPONENT PARTS 18 Upper or Lower Heating Elements 18 Capacitor 18 Transformer 18 Thermistors ambient suction discharge water out evaporator upper tank and lower tank 19 Fan Assembly 19 Water Pum...

Страница 3: ...ays 22 Figure 15 Replace Fan Assembly 23 Figure 16 Replace Water Pump 23 Figure 17 Replace Circuit Board 24 Figure 18 Wiring Diagram 25 Figure 19 Thermistor Resistance Chart 26 Before inspecting diagnosing repairing or operating any water heater be sure to examine all of the safety and warning labels on the tank Follow the instruction on these warning labels Read and understand the Use and Care Ma...

Страница 4: ... 4 1 0 a R e f r i g e r a n t This water heater contains a sealed gas refrigerant Please check your local licensing requirements to handle and service sealed refrigerant appliances Release of the refrigerant into the atmosphere may be considered illegal R 410A is an ozone friendly refrigerant designed to replace R 22 R 410A refrigerant does not contribute to ozone depletion The Clean Air Act mand...

Страница 5: ...Water Heater 4 Component Parts of the Heat Pump Water Heater Figure 1 HPWH Service Parts Part Name Description Picture User control 14 This panel allows for user selection of water temperature and operating mode ...

Страница 6: ... this heat pump are cold air and condensation Fan and Filter 8 9 EMB Papst Inc 1400 2200 RPM 240 V 1 phase 60 Hz Sealed ball bearing 49 db Filter must be cleaned periodically ECO upper thermistor and upper heating element 3 4 These are 2000 watt 240 volt stainless steel heating elements The thermostat thermistor is an electronic resistance device The ECO will trip at 1700 F if the water inside the...

Страница 7: ...ater in the tank Compressor 240V 1 phase 60 Hz Mitsubishi Electric Siam Compressor Industry 9 383 BTU HR nominal 5 8 amps rated load not repairable The compressor moves the R410a refrigerant around the heating loop The compressor serves two purposes The first is to circulate the refrigerant liquid through the circuit like a pump The other is to compress and raise the pressure and temperature of th...

Страница 8: ... be transferred to another location or part In the case of the HPWH the relays are used to control the routing of voltage to the heating elements and compressor during the various operating modes Filter Dryer not repairable The filter dryer removes any water vapor and moisture from the R410a refrigerant line Ambient Air Thermistor 15 Therm o disc 10 000 ohms thermistor Located on fan cover housing...

Страница 9: ...hms thermistor Measures the temperature of the discharge gasses This thermister is difficult to see It is on top of the compressor Suction Thermistor 18 Therm o disc 10 000 ohms thermistor Measures the temperature of the suction gasses Water Out Thermistor 19 Therm o disc 10 000 ohms thermistor Measures the temperature of the heated water from the heat exchanger to the water pump ...

Страница 10: ...rt of the refrigerant system It allows the R410a refrigerant to change from a high pressure gas to a low pressure gas Condensation Drain user installed drain line The heat pump will create a liquid called condensation This is the same condensation you find on the outside of a cold soda can This condensation must be discharged outside the home and may be governed by a local code Notice the NPT drai...

Страница 11: ...eter capable of 120 240 volts readings and Ohms resistance 1 element wrench Torx 20 screwdriver Error Code LED Light This LED will blink when there is a problem with the water heater Circuit Board 10 The circuit board controls all the electrical and temperature sensing inputs for the heat pump water heater Connections only go one way and are unique to each connection port ...

Страница 12: ...n modes In this mode compressor operation will not be allowed and only the auxiliary electric heat will be allowed Temperature set points noted with each of the modes will be used to turn the auxiliary electric heat on as required This mode can only be utilized on a short term basis Currently this mode will be allowed for a period of 2 weeks After this time period the water heater will attempt to ...

Страница 13: ...The default fan speed is low Low fan speed is obtained by power output to two fan leads the 3rd lead is common High speed operation is obtained by de energizing the low speed fan lead Operational Safety Controls all Modes The following controls are utilized to provide reliable heat pump operation for all operational Modes Thermistors will measure temperatures of both water and pressurized refriger...

Страница 14: ...T is not polled until after the additional delay b AS ambient temperature and WT water temperature leaving the condenser are polled If AS is less than 40ºF but not greater than 120ºF and WT is less than 132ºF compressor operation continues If not lower electric heating element operation is allowed Run Sequence 1 Fan speed will be held at the value determined during the Start Sequence 2 Water pump ...

Страница 15: ...e condenser are polled If AS is less than 40ºF but not greater than 120ºF and WT is less than 133ºF compressor operation continues If not lower electric heating element operation is allowed Run Sequence 1 Fan speed will be held at the value determined during the Start Sequence 2 Water pump will modulate speed as required 3 Compressor operation continues until lower tank thermostat or condenser wat...

Страница 16: ...ormal High Vacation mode temperature settings 6 This operating mode is maintained for a maximum of 2 weeks or 336 hours After this time period the water heater is returned to NORMAL operation Here is how the heating element electrical system works 1 Always 240V between ECO 1 3 even in heat pump modes 2 Always 240V between ECO 2 4 if ECO is not tripped 3 Always 120V at blue wire to each element 4 O...

Страница 17: ...ystem Troubleshooting E r r o r C o d e L E D L i g h t AN1 is red in color and is used to display diagnostic codes Flash rate is 0 33 seconds on 0 33 seconds off with 2 0 seconds off between flash codes Flash codes are as follows Figure 6 Error Code LED Steady On After 120 second anti short cycle period No fault present Steady Off No power to control or control board fault 1 Flash Compressor off ...

Страница 18: ...water heater Replace water heater Unit runs but short cycles on Thermostat defective Refrigerant line leaking Restriction in expansion valve Check tank thermistors Replace water heater Replace water heater Unit operates long or continuously Dirty air filter Evaporator coil iced Dirty heat exchanger Clean or replace Determine reason and correct Clean heat exchanger coils Suction line frosted or swe...

Страница 19: ...eck for a grounded element 4 With the power remaining off place one test probe on either of the screw terminals and the other test probe to the steel inner tank If the OHM meter registers any resistance the element is grounded and should be replaced C a p a c i t o r The capacitor boosts power to help the compressor start and run 1 Measure for 240VAC on the red wire to the capacitor and the black ...

Страница 20: ...from the circuit board 6 Measure ohms resistance between the two wires of the thermistor 7 Compare this resistance to the chart on the last page and determine the temperature Figure 9 Thermistor Connections F a n A s s e m b l y 1 Cycle the water heater to Energy Saver or Normal mode The fan does not work in electric heat only mode 2 You should hear the fan running 3 Locate the fan motor Molex on ...

Страница 21: ...lay switches on the HPWH The purpose of the relay switch is to send power and control certain component parts With the control board they control the compressor upper heating element and lower heating element The control board sends out the 240 volt signal thru the respective wires from the P7 connection black for compressor orange for upper heating element blue for lower heating element Figure 12...

Страница 22: ... shut off valve Open a hot water faucet or the T P valve to relieve the pressure inside the tank Open the drain valve at the bottom of the tank and drain water to below the level of the element 3 Remove both wires from the element terminal screws 4 With a 1 1 2 inch hex socket wrench remove the element Check the shoulders of the element seat on the tank and remove any remainder of the gasket mater...

Страница 23: ...e two screws 5 Return power to the water heater and check for safe operation Figure 14 Replace Capacitor or Relays T r a n s f o r m e r 1 Turn off power to the water heater 2 Using a flat blade screwdriver or inch nut driver remove the two screws holding the transformer 3 Disconnect the wire leads one side at a time and attach to new transformer 4 Secure replacement transformer in place with the ...

Страница 24: ...e the tank Open the drain valve at the bottom of the tank and drain water to below the level of the element 3 Disconnect the wiring harness to the water pump 4 Remove the four Torx 20 screws from the pump They may be some residual water leaking when you remove the pump 5 Mount the new pump and new o ring Tighten the four Torx 20 screws 6 Reconnect wiring harness 7 Open the cold water isolation val...

Страница 25: ... remove them with the connector number from the board This is especially important for the thermistors 6 Press the plastic spring clips of the retainers at the four corners of the board Remove the board and leave the spring clips on the water heater 7 Replace board on the four spring clips 8 Reconnect all Molex connections 9 Return power to the water heater and check for safe operation Figure 17 R...

Страница 26: ...Heat Pump Water Heater 25 Wiring Connection Diagram Figure 18 Wiring Diagram ...

Страница 27: ... 46 115 4 203 80 176 1 255 14 57 18 090 47 117 4 042 81 178 1 215 15 59 17 255 48 118 3 889 82 180 1 177 16 61 16 464 49 120 3 743 83 181 1 140 17 63 15 714 50 122 3 603 84 183 1 104 16 61 15 000 51 124 3 469 85 185 1 070 17 63 14 323 52 126 3 340 86 187 1 037 18 64 13 681 53 127 3 217 87 189 1 005 19 66 13 071 54 129 3 099 88 190 974 20 68 12 493 55 131 2 986 89 192 944 21 70 11 942 56 133 2 878 ...

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