Daikin Altherma HT Service Manual

Troubleshooting by Indication on the Remote Controller ESIE09-08B
140 Troubleshooting
3.7 “C4” Indoor Unit: Malfunction of Thermistor (R3T) Liquid
Thermistor R-410A
Remote Control
Display
C4
Subcode 0
Applicable
Models
All indoor unit models
Method of
Malfunction
Detection
Malfunction detection is carried out by temperature detected by liquid thermistor.
Malfunction
Decision
Conditions
When the liquid thermistor becomes disconnected or shorted while the unit is running.
Supposed
Causes
 Defect of thermistor (R3T) for liquid pipe
 Defect of indoor unit PC board (A1P)
Troubleshooting
 Refer to thermistor resistance / temperature characteristics table on P239.
Caution
Be sure to turn off power switch before connect or disconnect
connector, or parts damage may be occured.
(V2784)
Replace the indoor unit PC board (A1P).
Connect the thermistor and turn
on again.
Bad wiring connection
value < -43.6°C
Faulty thermistor
value > 115°C
NO
NO
Replace the thermistor (R3T).
YES
YES
Connector
is connected to X18A
of the indoor unit PC board
(A1P).
Resistance
is normal when
measured after
disconnecting the thermistor
(R3T) from the indoor unit PC
board
(0.5k
~360k )

Daikin Altherma HT Specifications

General

Type	Air-to-water heat pump
Refrigerant	R-410A
Water Outlet Temperature	Up to 80°C
Operating Temperature Range	-20°C to 35°C
Power Supply	3-phase, 400V
Energy Efficiency Class (Heating)	A++