Panasonic WH-MXC16J9E8 Service Manual page 178

17.5.34 Refrigeration Cycle Abnormality (F24)
Malfunction Decision Conditions:
1 During operation running (heating / cooling) for more than 5 minutes expect deice, pumpdown and test mode.
2 During heating / cooling, water outlet and water inlet difference is less than 3°C (Heating) / 2°C (Cooling).
3 During heating / cooling, high pressure < 1.90MPa (275 Psi) for more than 10 minutes or < 1.6MPa (232 Psi)
for more than 10 minutes.
4 During heating / cooling, discharge temperature - saturation temperature of high pressure ≥ 65°C (Heating) /
70°C (Cooling).
5 During heating / cooling, high pressure < 0.5MPa (72 Psi) for more than 4 minutes".
Malfunction Caused:
1 Refrigerant shortage (refrigerant leakage).
2 Faulty indoor water inlet, indoor water outlet, compressor discharge temp sensor or high pressure sensor.
3 2/3 way valve closed.
4 Clogged expansion valve or strainer.
5 Faulty outdoor unit PCB (main).
6 Poor compression of compressor.
Abnormality Judgment:
Continue 2 times in 30 minutes.
Check for gas leaking
Is the leaking found?
No
Check sensor characteristics
1. Water outlet sensor
2. Water inlet sensor
3. Compressor discharge sensor
Does it conform to
sensor characteristics?
Yes
Check the pressure sensor
Is the pressure sensor value
and actual mismatched?
No
Yes
Repair leak point or replace,
reclaim and recharge gas
No
Replace the sensor
Yes
Replace the pressure sensor
Check for clogged expansion
valve or strainer
Is the expansion valve or strainer
clogged (ice formed)?
No
Reclaim and recharge for a specified
amount of fresh refrigerant
Is abnormality happened again?
No
178
Yes
- Replace expansion valve and / or
strainer
- Reclaim and recharge refrigerant
Yes
- Replace the outdoor or indoor unit
PCB (main)
Procedure complete