Daikin Altherma EKHBH Series Service Manual page 133

ESIE06-03
"U7" Malfunction of Transmission between Remote Controller and Control box
4.5
U7
Error code
Method of Communication error between microcomputer mounted on the main microcomputer and PM1.
malfunction
detection
Malfunction
decision conditions
Supposed causes
Troubleshooting
Turn the power off and turn it on
again.
Caution Be sure to turn off power switch before connect or disconnect connector, or parts damage may be
occurred.
Part 3 – Troubleshooting
When the data sent from the PM1 can not be received successively for 9 sec.
The abnormality is determined if the above fault conditions occurs once.
Fault counter is reset when the data from the PM1 can be successfully received.
Defective outdoor unit PCB
Error again?
NO
YES
Error Codes: System Malfunctions
Replace the outdoor unit PCB.
The cause can be an external
factor other than the
malfunction.
Monitor in long term.
1
3 3
4
5
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