U5-00 - User Interface Communication Problem - Daikin altherma 3 M Service Manual

2 | Troubleshooting
2.3.73 U5-00 – User interface communication problem
Service manual
60
Possible cause:
▪ Faulty or disturbance of the power supply (imbalance >4%),
▪ Power drop,
▪ Short circuit.
2 Check the wiring between the hydro PCB and the main PCB. See
4
circuit" [ 284].
Possible cause: Faulty wiring between the hydro PCB and main PCB.
3 Perform a check of the main PCB. See
Possible cause: Faulty main PCB.
4 Perform a check of the outdoor unit fan motor. See
4
motor" [ 217].
Possible cause: Faulty outdoor unit fan motor.
5 Perform a check of the hydro PCB. See
Possible cause: Faulty hydro PCB.
Prerequisite: Stop the unit operation via the user interface.
6 Turn OFF the respective circuit breaker.
DANGER: RISK OF ELECTROCUTION
Confirm the rectifier voltage is below 10 V DC before proceeding, see
electrical hazards" [
7 Check that the thermal interface grease is applied properly on the (PCB or
refrigerant piping) contact surface of the heat sink. Adjust if needed.
Possible cause: Thermal interface grease NOT applied properly on the heat
sink.
INFORMATION
Make sure to use thermal interface grease Shin Etsu G-776 (spare part number
2269571).
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
Trigger
Communication failure
between unit and user
interface.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1 Perform a check of the hydro PCB. See
Possible cause: Faulty hydro PCB.
"3.14 Main
"3.12 Hydro
4
285].
Effect
Unit will stop operating.
"3.12 Hydro
"4.1 Electrical
4
PCB" [ 171].
"3.16 Outdoor unit fan
4
PCB" [ 160].
"To prevent
Reset
Automatic reset.
4
PCB" [ 160].
EBLA09~16DA + EDLA09~16DA
Daikin Altherma 3 M
ESIE20-06A – 2021.03