Panasonic WH-ADF0309J3E5CM Service Manual page 271

25.2.24 Outdoor High Pressure Switch Activate (F94 / P04 / F12)
Malfunction Decision Conditions:
During operation of cooling and heating, when pressure 4.5 MPa and above is detected by outdoor high pressure
switch.
Malfunction Caused:
1. Dust accumulation on the outdoor unit heat exchanger.
2. Air short circuit at outdoor unit.
3. Faulty water pump.
4. Insufficient water flow rate in system.
5. Water leak in system.
6. 2/3 way valve closed.
7. Clogged expansion valve or strainer.
8. Excessive refrigerant.
9. Faulty outdoor high pressure sensor and switch.
10. Faulty outdoor unit PCB.
Abnormality Judgment:
Continue 4 times in 20 minutes.
Troubleshooting:
Check the dust accumulation on the
outdoor unit heat exchanger.
Is the outdoor unit heat
exchanger dirty?
No
Check the outdoor air
passage.
Is there any short circuit?
No
Check the system water pump.
Is the water pump working?
Yes
Check the system water
flow rate.
Is the water pump speed
adjusted according to system
hydraulic external static pressure?
Yes
Caution
Yes
Clean the heat exchanger.
Yes
Provide sufficient air
passage.
- Replace the faulty water
No
pump.
- Replace outdoor high
pressure sensor.
- Readjust the water pump
No
speed.
- Replace outdoor high
pressure sensor.
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Check the 2/3 way valve.
Is the 2/3 way valve closed?
No
Check the system water passage.
Is there any water leakage?
No
Check for clogged
expansion valve or strainer.
Is the expansion valve or
strainer clogged (ice formed)?
No
Check refrigerant amount.
Is the additional refrigerant
amount filled correctly?
Yes
271
Yes
Open the 2/3 way valve.
Yes - Fix the system water leakage.
- Replace outdoor high
pressure sensor.
- Replace the expansion valve
and/or strainer.
Yes
- Reclaim and recharge
refrigerant.
- Replace outdoor high
pressure sensor.
- Reclaim and recharge with
No
correct amount of refrigerant.
- Replace outdoor high
pressure sensor.
- Replace the outdoor unit
PCB (main).
- Replace the outdoor high
pressure sensor and switch.