C9" Indoor Unit: Return Water Thermistor (R4T) - Daikin ALTHERMA HT Service Manual

Troubleshooting by Indication on the Remote Controller
"C9 " Indoor Unit: Return Water Thermistor (R4T)
3.9
C9
Remote Control
Display
Subcode 0
AII indoor unit models
Applicable
Models
Malfunction detection is carried out by temperature detected by return water temperature
Method of
thermistor.
Malfunction
Detection
When the return water temperature thermistor becomes disconnected or shorted while the unit
Malfunction
is running.
Decision
Conditions
 Defect of indoor unit thermistor (R4T) for water return
Supposed
 Defect of indoor unit PC board (A1P)
Causes
Troubleshooting
 Refer to thermistor resistance / temperature characteristics table on P239.
142
Be sure to turn off power switch before connect or disconnect
connector, or parts damage may be occured.
Caution
Connector is
NO
connected to X12A of
the indoor unit PC
board.
YES
Resistance
is normal when
measured after
NO
disconnecting the thermistor
(X12A) (R4T) from the
indoor unit PC board.
(7.2k ~112k )
YES
Bad wire connection
Connect the thermistor and turn
value < -43.6 C
on again.
Faulty thermistor
value > 95 C
ESIE09-08B
Replace the thermistor (R4T).
Replace the indoor unit PC board (A1P).
(V2786)
Troubleshooting