Troubleshooting
Si10-417
64
Service Diagnosis
5.2.19 Four Way Valve Abnormality
Remote
Controller
Display
EA
Outdoor
Unit LED
Display
A
5
1
4
2
1
3
1
4
1
Method of
Malfunction
Detection
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 operating mode.
Malfunction
Decision
Conditions
Either of the following conditions occurs 3 minutes after
the compressor has started.
Cooling / dry operation
(Outdoor unit heat exchanger temperature – Liquid
pipe temperature) < –5°C
Heating operation
(Liquid pipe temperature – Outdoor unit heat
exchanger temperature) < –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
Si10-417.fm Page 64 Wednesday, September 22, 2004 6:38 PM
