Daikin FTKS50BVMB, Service Manual

Page: 335 / 456

SiEN18-622 Troubleshooting for RA Indoor Unit
Troubleshooting 323
4.2 Freeze-up Protection Control or High Pressure Control
Remote Control
Display
A5
Method of
Malfunction
Detection „ High pressure control (heat pump model only)
During heating operations, the temperature detected by the indoor heat exchanger
thermistor is used for the high pressure control (stop, outdoor fan stop, etc.)
„ The freeze-up protection control (operation halt) is activated during cooling operation
according to the temperature detected by the indoor unit heat exchanger thermistor.
Malfunction
Decision
Conditions „
High pressure control
During heating operations, the temperature detected by the indoor heat exchanger
thermistor is above 65°C
„ Freeze-up protection
When the indoor unit heat exchanger temperature is below 0°C during cooling operation.
Supposed
Causes „
Operation halt due to clogged air filter of the indoor unit.
„
Operation halt due to dust accumulation on the indoor unit heat exchanger.
„ Operation halt due to short-circuit.
„
Detection error due to faulty indoor unit heat exchanger thermistor.
„ Detection error due to faulty indoor unit PCB.