Daikin AT12BV1LS Pocket Manual page 65

Troubleshooting
5.2.19 Four Way Valve Abnormality
Remote
Controller
Display
Outdoor
Unit LED
Display
Method of
Malfunction
Detection
Malfunction
Decision
Conditions
Supposed
Causes
64
EA
A 1 2
5 4
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.
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
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
3 4
1 1 1
Si10-417
Service Diagnosis