Panasonic WH-ADF0309J3E5CM Service Manual page 267

25.2.21 Outdoor High Pressure Error (H98 / - / H98)
Malfunction Decision Conditions:
During operation of heating, when pressure 4.0 MPa and above is detected by outdoor high pressure sensor.
Malfunction Caused:
1. Faulty water pump.
2. Insufficient water flow rate in system.
3. Water leak in system.
4. Dust accumulation in the outdoor unit heat exchanger.
5. Air short circuit at outdoor.
6. Faulty outdoor unit fan motor.
7. 2/3 way closed.
8. Clogged expansion valve or strainer.
9. Excessive refrigerant.
10. Faulty outdoor high pressure sensor.
11. Faulty outdoor unit PCB (main).
12. Room indoor clogged air filter or heat exchanger
13. Over-bent pipe
Troubleshooting:
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
Check the system water passage.
Is there any water leakage?
No
Caution
Heating / Tank
No
Replace the faulty water
pump.
No
Readjust the water
pump speed.
Yes
Fix the system water
leakage.
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Operation Mode
(Tank Unit)
Check the 2/3 way valve.
Is the 2/3 way valve closed?
Check for clogged expansion
valve or strainer.
Is the expansion valve or
strainer clogged (ice formed)?
Check refrigerant amount.
Is the additional refrigerant
amount filled correctly?
267
Yes
Open the 2/3 way valve.
No
- Replace the expansion
Yes
valve and/or strainer.
- Reclaim and recharge
refrigerant.
No
Reclaim and recharge with
No
correct amount of
Yes Yes
- Replace the outdoor unit
PCB (main).
- Replace the outdoor high
pressure sensor.
refrigerant.