Four Way Valve Abnormality - Daikin D-Series Service Manual

Si12-619A
5.16

Four Way Valve Abnormality

EA
Remote
Controller
Display
Outdoor Unit LED A
Display
Method of The liquid pipe 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
Malfunction
operating mode.
Detection
Malfunction Either of the following conditions occurs 6 minutes after the compressor has started.
Decision
Conditions
Supposed
Causes
Service Diagnosis
1 2 3 4
5 4 1 1
Cooling / dry operation
(Outdoor unit heat exchanger temperature – Liquid pipe temperature) < –5°C
Heating operation
(Liquid pipe temperature – Outdoor unit heat exchanger temperature) < 0°C
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
1
Troubleshooting
231