Four-Way Valve Abnormality - Daikin FTXS09HVJU Service Manual

Troubleshooting

4.11 Four-Way Valve Abnormality

4.11.1 09/12 Class
EA
Remote
Controller
Display
The indoor air temperature thermistor, the indoor unit heat exchanger thermistor, the outdoor
Method of
temperature thermistor and the outdoor unit heat exchanger thermistor are checked to see if they
Malfunction
function within their normal ranges in the operating mode.
Detection
Malfunction A following condition continues over 10 minutes after operating 5 minutes.
 Cooling / dry operation
Decision
Conditions
 Heating
 Connector in poor contact
Supposed
 Thermistor defective
Causes
 Outdoor unit PCB defective
 Four-way valve coil or harness defective
 Four-way valve defective
 Foreign substance mixed in refrigerant
 Refrigerant shortage
Service Diagnosis
(room temp. – indoor heat exchanger temp.) < –9°F (–0.5°C)
(indoor unit heat exchanger temp. – room temp.) < –9°F (–0.5°C)
SiUS04-904
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