Mitsubishi multi city 6607 error

[Jamjuice]

Hi there,

Ive got a an error code 6607 on a Mitsubishi system. Happened 3 times over about a month or two period. 2 indoor units. Other unit working fine. System has been running fine for several years prior to this error. Turning thermostat off and on makes it work again.

“ The error is detected when no acknowledgement (ACK signal) is received after the transmission. (eg. When the data is trans- mitted six times in a row with 30 seconds interval, the error is detected on the transmission side.) Part of the indoor units (IC) are experiencing problems.”

Any tips would be greatly appreciated.

Thanks kindly,
Jam

[narkom]

Check the indoor-outdoor transmission line voltage on the farthest indoor unit, terminals M1-M2. Should be 24...30VDC. If no, check the loosing contacts etc.