Heater Wire Abnormality - Daikin FTXZ25NV1B Service Manual

SiMT041311E

2.31 Heater Wire Abnormality

PA
Error Code
Method of Error An error is identified when the outlet temperature of humidifying fan does not reach a certain
temperature within a given time after the heater is turned on.
Detection
Error Decision The temperature detected by the humidifying thermistor is lower than the outdoor temperature
(with the heater turned off) + 6°C, and this condition continues for 30 minutes.
Conditions
Supposed
Causes
Troubleshooting
Check No.01
Refer to P.181
[
At normal temperature:
97 Ω ± 10%
Service Diagnosis
Power supply voltage is extremely low.
Breakage of heater filament
Breakage of heater harness
Abnormal temperature detected by outdoor temperature thermistor
Abnormal temperature detected by humidifying thermistor
Defective main relay
Blown thermal fuse
Defective heater control part
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
Is the
power supply voltage
appropriate?
Turn off the power.
Is the heater well cooled?
Measure the resistance
between the heater connectors.
Is the heater
resistance
appropriate?
]
Is the thermal fuse blown?
Check No.01
Is a resistance of the
humidifying thermistor
appropriate?
NO
YES
NO
YES
NO
YES
YES
NO
NO
YES
Troubleshooting
Modify the power supply
voltage.
Cool it down.
Replace the heater ASSY.
Replace the heater ASSY.
Replace the thermistor.
*Refer to PH
troubleshooting.
Replace the indoor unit
PCB (A1P).
*Main relay may be
damaged.
When the main relay
(MRM10) is damaged,
heater and rotor do not run.
(R19689)
164