Daikin D-Series User Manual

Si18-525B Troubleshooting for SkyAir Indoor Unit
Troubleshooting 351
5.9 Malfunction of Heat Exchanger Thermistor (R3T)
Remote
Controller
Display
C5
Applicable
Models
FFQ, FCQ, FBQ, FHQ
Method of
Malfunction
Detection
Malfunction detection is carried out by temperature detected by heat exchanger sensor (R3T).
Malfunction
Decision
Conditions
When the heat exchanger thermistor becomes disconnected or shorted while the unit is running.
Supposed
Causes

Failure of the sensor itself

Broken or disconnected wire

Failure of electronic circuitry (indoor unit PCB)

Failure of connector contact
Troubleshooting
Check No.02
Refer to P.358
Disconnect the heat exchange
sensor (R3T) from X17A on
the indoor unit PC board and
measure the resistance.
Connect correctly.
Heat exchanger
sensor replacement.
If contact is OK,
replace indoor unit
PCB.
Is the
thermistor normal?
(See note)
NO
NO
YES
YES
(Q0417)
Check contact of connector
Is it normal?
+See Check No. 02 for “Thermistor temperature and resistance characteristics”.
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.

Daikin D-Series Specifications

General

HSPF Rating	Up to 10.0
Cooling Capacity	9, 000 - 36, 000 BTU/h
Heating Capacity	9, 000 - 36, 000 BTU/h
Energy Efficiency Ratio (EER)	Up to 12.5
Sound Level	19 - 50 dB (Indoor), 49 - 60 dB (Outdoor)
Noise Level	19 - 50 dB (Indoor), 49 - 60 dB (Outdoor)
Power Supply	208/230V, 1-phase, 60Hz