195
16.5.35 Four Way Valve Abnormality (F25)
Malfunction Decision Conditions:
1 During heating operation, when the indoor pipe temperature of thermostat ON indoor unit < 0°C.
2 During cooling operation, when the indoor pipe temperature of thermostat ON indoor unit > 45°C.
Malfunction Caused:
1 Faulty
sensor.
2 Faulty
connector
connection.
3 Faulty outdoor unit PCB (noise filter/main).
4 Faulty four way valve.
Abnormality Judgment:
Continue 4 times in 30 minutes.
Is F25 occur during heating
operation?
Is the four way valve coil energize
during cooling operation?
No
Check the indoor pipe
temperature sensor.
Replace the indoor pipe
temperature sensor.
No
Does it conform to the
sensor characteristic chart?
Yes
Four way valve coil
disconnected (loose)?
Reconnect the harness.
Yes
Is the harness out of the
CN-HOT connector?
No
Replace the outdoor unit
PCB (noise filter/main).
Yes
Correct the four way valve
coil.
Yes
Check the continuity of the
four way valve coil.
Replace the four way valve
coil.
No
Disconnect the harness from the
CN-HOT connector. Resistance
between harness about 1.52k ohm?
No
Measure AC voltage supply to
CN-HOT (pin1 & 3) during heating
operation.
Is the voltage supply to four
way valve 230Vac?
Replace the outdoor unit
PCB (noise filter/main).
Replace the four way valve.
Replace the four way valve.
No
Yes
Yes
No
Yes
Troubleshooting:
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Caution