Daikin Altherma HT Service Manual

ESIE09-08B Troubleshooting by Indication on the Remote Controller
Troubleshooting 141
3.8 “C5 ” Indoor Unit: Malfunction of Tank Thermistor (R2T)
Remote Control
Display
C5
Subcode 0
Applicable
Models
All indoor unit models
Method of
Malfunction
Detection
Malfunction detection is carried out by temperature detected by tank thermistor.
Malfunction
Decision
Conditions
When the tank thermistor becomes disconnected or shorted while the unit is running.
Supposed
Causes
 Defect of indoor unit tank thermistor (R2T)
 Defect of indoor unit PC board (A3P)
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.
(V2785)
Replace the indoor unit PC board (A3P).
Connect the thermistor and turn
on again.
NO
NO
Replace the thermistor (R2T).
Faulty thermistor
value > 90˚C
Bad wire connection
value < -35.7˚C
YES
YES
YES
Resistance
is normal
when measured after
disconnecting the thermistor
(R2T) from the indoor
unit PC board.
(1.6k
~360k )
Connector
is connected to
X11A of the indoor unit
PC board A3P.
Make setting, restart unit.
NO
Check if
DHW option is
turned rightful active
[6-00].

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++