U7-00 - Outdoor Unit: Transmission Malfunction Between Main Microcomputer - Inverter Microcomputer; U8-02 - Connection With Room Thermostat Lost - Daikin EBLA04E V Series Service Manual

3.3.80 U7-00 – Outdoor unit: Transmission malfunction between main microcomputer - inverter
microcomputer
3.3.81 U8-02 – Connection with room thermostat lost
EBLA04~08E + EDLA04~08E
Daikin Altherma 3 M
ESIE22-09 – 2022.05
Trigger
Communication
abnormality between
main and inverter
microcomputer.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1 Perform a check of the main PCB. See
Possible cause: Faulty main 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
after connection was
already made.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1 Check if the power supply is compliant with the regulations. See
4
circuit" [ 254].
Possible cause:
▪ Faulty or disturbance of the power supply (power supply MUST be within
range of nominal operating voltage ±4%),
▪ Power drop,
▪ Short circuit.
2 Check the communication wiring between the remote controller and the unit.
See "4.20 User interface" [
Possible cause: Faulty wiring between the remote controller and the unit.
3 Perform a check of the room thermistor:
Effect
Unit will stop operating.
"4.14 Main
Effect
Unit will NOT stop
operating.
4
234].
draft – 31/05/2022 15:53
3 | Troubleshooting
Reset
Manual reset via user
interface.
4
PCB" [ 184].
Reset
Automatic reset.
"5.1 Electrical
Service manual
73