Daikin R407C PLUS - Outdoor Unit: Malfunction of Thermistor (R2 T) for Heat Exchanger

Troubleshooting Si33-105
178 Troubleshooting R407C PLUS Series Heat Recovery System
3.22 Outdoor Unit: Malfunction of Thermistor (R2T) for Heat
Exchanger
Remote
Controller
Display
J6
Supposed
Causes
!
Defect of thermistor (R21T, R22T or R23T) for outdoor unit coil
!
Defect of outdoor unit PC board (A1P)
Troubleshooting
The alarm indicator is displayed when the fan is being used also.
Note: 16~20HP class ··· R21T, R22T (A1P)
24~30HP class ··· R21T, R22T (A1P), R23T (A3P)
(VF048)
Resistance
is normal when
measured after
disconnecting the thermistor
(R21T, R22T or
R23T) from the outdoor
unit PC board.
(3.5kΩ~
360kΩ)
Replace outdoor unit PC board
A1P or A3P.
Connect the thermistor and turn
on again.
NO
NO
Replace the thermistor (R21T,
R22T or R23T)
YES
YES
Connector
is connected to X18A,19A
or X71A of outdoor unit PC
board (A1P or
A3P).
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.