175
16.5.15 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.
Check if external water pump
is used and it is directly
installed to the air-to-water
heatpump indoor unit circuit.
(without buffer tank)
During deice (mode 2), check if
indoor unit water pump operates.
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.
- Defect in indoor unit water
flow switch
- Replace the indoor unit
water flow switch
Is there any continuity?
Yes
No
Use buffer tank to
● 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.
separate external
water pump from
air-to-water
heatpump indoor
unit circuit.
- Defect in indoor unit PCB
- Replace the indoor unit PCB
Yes
No
Yes
No
Turn OFF the power.
Disconnect indoor unit
water pump connector
CN-PUMP1. Operate
the air-to-water
heatpump unit. During
deice (mode 2), check if
the indoor unit water
pump duty command
signal generated?
- Defect in indoor unit water
pump
- Replace the indoor unit
water pump
No
- Defect in indoor unit PCB
- Replace the indoor unit PCB
Yes
Troubleshooting:
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Caution