Daikin FTKS20D2VMWL, Service Manual

Page: 134 / 228

SiENBE04-507A Troubleshooting
Service Diagnosis 125
4.13 Four Way Valve Abnormality
Remote
Controller
Display
EA
Method of
Malfunction
Detection
The indoor air temperature thermistor, the indoor unit heat exchanger thermistor, the outdoor
temperature thermistor and the outdoor unit heat exchanger thermistor are checked to see if
they function within their normal ranges in the operating mode.
Malfunction
Decision
Conditions
A following condition continues over 10 minute after operating 5 minutes.
„
Cooling / dry operation
(room temp. – indoor heat exchanger temp.) < –5°C
„ Heating
(indoor unit heat exchanger temp. – room temp.) < –5°C
Supposed
Causes
„ Connector in poor contact
„ Thermistor defective
„
Outdoor unit PCB defective
„ Four way valve coil or harness defective
„ Four way valve defective
„ Foreign substance mixed in refrigerant
„ Insufficient gas