Panasonic WH-UD05JE5 Service Manual page 204

19.5.15 Deice Circulation Error (H65)
Malfunction Decision Conditions:
During startup and operation of deice (mode 2), the water flow (> 10l/min) detected by the water flow switch is
used to determine deice circulation error.
Malfunction Caused:
1 Water flow in air-to-water heatpump indoor unit circuitry.
2 Faulty indoor unit water flow switch.
3 Faulty indoor unit water pump.
4 Faulty indoor unit PCB.
Abnormality Judgment:
Continue for 10 seconds.
Troubleshooting:
During deice (mode 2), check if indoor
unit water pump operates.
Check if internal water pump is
used and it is directly installed to
the air-to-water heatpump
indoor unit circuit. (without buffer
Stop operation and turn OFF power.
Plug out the connector of water flow
switch (CN-FLOW) in the indoor unit
PCB and measure its continuity.
Is there any continuity?
Turn OFF the power.
Disconnect indoor unit water
pump connector CN-PUMP1.
Operate the auto-water
heatpump unit. During deice
(mode 2), check if the indoor
unit water pump duty
command signal generated?
Caution
No
Yes
tank)
No
Yes
No
- Defect in indoor unit water
No
- Replace the indoor unit
Yes
- Defect in indoor unit PCB.
- Replace the indoor unit PCB.
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Use buffer tank to
separate external water
pump from air-to-water
heatpump indoor unit
circuit.
- Defect in indoor unit water
flow switch.
- Replace the indoor unit
water flow switch.
- Defect in indoor unit PCB.
- Replace the indoor unit PCB.
pump.
water pump.
204
CAUTION
Panasonic
Air-to-Water
Heatpump
Indoor Unit
● When external pump is used, be sure to install
it in independent water circuit and not direct to
the air-to-water heatpump indoor unit circuit.
External
Pump