Daikin D-Series User Manual

Troubleshooting for Outdoor Unit Si18-525B
376 Troubleshooting
7.11 Malfunction of Thermistor (R4T) for Outdoor Unit Heat
Exchanger
Remote
Controller
Display
J6
Applicable
Models
AII outdoor unit models
Method of
Malfunction
Detection
Malfunction is detected from the temperature detected by the heat exchanger thermistor.
Malfunction
Decision
Conditions
When a short circuit or an open circuit in the heat exchange thermistor is detected.
Supposed
Causes

Defect of thermistor (R4T) for outdoor unit heat exchanger

Defect of outdoor unit PCB (A1P)
Troubleshooting
∗
Refer to thermistor resistance / temperature characteristics table on P398.
(Q0431)
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
Resistance
is normal when
measured after
disconnecting the thermistor
R4T from the outdoor
unit PCB.
(3.5kΩ~
360kΩ)
Replace outdoor unit PCB A1P.
Connect the thermistor and turn
on again.
NO
NO
Replace the thermistor R4T.
YES
YES
Connector
is connected to outdoor
unit PCB
(A1P).

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