Freeze-Up Protection Control - Daikin MKS-T Series Service Manual

SiSG121917E
5.2

Freeze-up Protection Control

A5
Error Code
Method of Error
During cooling operation, the freeze-up protection control (operation halt) is activated according
Detection to the temperature detected by the indoor heat exchanger thermistor.
Error Decision During cooling operation, the indoor heat exchanger temperature is below 0°C.
Conditions
Supposed
 Short-circuited air
Causes  Clogged air filter of the indoor unit
 Dust accumulation on the indoor heat exchanger
 Defective indoor heat exchanger thermistor
 Defective indoor unit PCB
Troubleshooting
Reference
Check No.01 Refer to P.169
Part 6 Service Diagnosis
Troubleshooting for Wall Mounted and LSP Duct Type Indoor Unit
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
Check the air passage.
Is there any short circuit?
NO
Check the air filter.
Dirty?
NO
Check the dust accumulation on
the indoor heat exchanger.
Dirty?
NO
Check No. 01
Check the indoor heat exchanger
thermistor.
As
described in the
thermistor characteristic
chart?
YES
YES
YES
YES
NO
Provide sufficient air passage.
Clean the air filter.
Clean the indoor heat
exchanger.
Replace the indoor heat
exchanger thermistor.
Replace the indoor unit PCB
(control PCB).
(R20789)
118