U8-03 - No Connection With Room Thermostat - Daikin altherma 3 M Service Manual

2 | Troubleshooting
2.3.76 U8-03 – No connection with room thermostat
Service manual
62
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1 Check if the power supply is conform with the regulations. See
circuit" [ 4 284].
Possible cause:
▪ Faulty or disturbance of the power supply (imbalance >4%),
▪ Power drop,
▪ Short circuit.
2 Check the communication wiring between the remote controller and the unit.
See "3.21 User interface" [
Possible cause: Faulty wiring between the remote controller and the unit.
3 Perform a check of the room thermistor:
▪ Measure the room temperature and compare to the room temperature
shown on the user interface (remote controller).
▪ If temperature shown on the user interface differs from the measured
temperature, replace the user interface (remote controller). See
documentation of the user interface (remote controller) for more
information.
Possible cause: Faulty room thermistor.
4 Perform a check of the hydro PCB. See
Possible cause: Faulty hydro PCB.
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
Trigger
Communication
abnormality between unit
and room thermostat,
connection NOT possible.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1 Check if the power supply is conform with the regulations. See
4
circuit" [ 284].
Possible cause:
▪ Faulty or disturbance of the power supply (imbalance >4%),
▪ Power drop,
▪ Short circuit.
2 Perform a check of the room thermistor:
4
266].
"3.12 Hydro
Effect
Unit will NOT stop
operating.
"4.1 Electrical
4
PCB" [ 160].
Reset
Automatic reset.
"4.1 Electrical
EBLA09~16DA + EDLA09~16DA
Daikin Altherma 3 M
ESIE20-06A – 2021.03