Daikin Altherma HT Service Manual

ESIE09-08B Troubleshooting by Indication on the Remote Controller
Troubleshooting 173
3.32 “J9 ” Outdoor Unit: Malfunction of Thermistor (R4T) for
Subcooling Heat Exchanger Gas Pipe
Remote Control
Display
J9
Applicable
Models
ER*Q 011~016*
Method of
Malfunction
Detection
Malfunction is detected according to the temperature detected by subcooling heat exchanger
gas pipe thermistor.
Malfunction
Decision
Conditions
When the subcooling heat exchanger gas pipe thermistor is short circuited or open.
Supposed
Causes
 Faulty subcooling heat exchanger gas pipe thermistor (R4T)
 Faulty outdoor unit PC board
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.
(V3075)
Is the
resistance
measured after
removing the thermistor
(R4T) from outdoor unit PC
board normal?
(3.5 kΩ to 360 kΩ)
Replace outdoor unit PC board
(A1P).
Connect connector and operate
unit again.
NO
NO
Replace thermistor (R4T).
YES
YES
Is the
connector for
subcooling heat
exchanger gas pipe
thermistor connected to
X12A of outdoor unit
PC board
(A1P)?

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++