Freeze-Up Protection Control/Heating Peak-Cut Control - Daikin FTX-N Series Service Manual

SiUS041638EA
4.3

Freeze-up Protection Control/Heating Peak-cut Control

A5
Error Code
Method of Error
 Freeze-up protection control
Detection
 Heating peak-cut control
Error Decision
 Freeze-up protection control
Conditions
 Heating peak-cut control
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
Check No.01
Refer to P.94
Service Diagnosis
During cooling operation, the freeze-up protection control (operation halt) is activated according
to the temperature detected by the indoor heat exchanger thermistor.
During heating operation, the temperature detected by the indoor heat exchanger thermistor is
used for the heating peak-cut control (operation halt, outdoor fan stop, etc.)
During cooling operation, the indoor heat exchanger temperature is below 0°C (32°F).
During heating operation, the indoor heat exchanger temperature is above about 60°C (140°F)
(depending on the model).
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
Troubleshooting
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).
(R21064)
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