Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual page 39

1302 (UE): High pressure trouble
Diagnosis of failure
Continued from the previous page.
Is the indoor unit filter clogged?
Is there dirt on the indoor heat
exchanger?
Is the outdoor unit short-cycled?
Is there dirt on the outdoor heat
exchanger?
Are the pipes clogged or broken?
Disconnect the TH7 wiring and check the
resistance.
Continue to the next page.
OCH800A_39
Yes
(Clogged filter)
No
(Not clogged)
Yes
(Dirty)
No
(Not dirty)
Yes
(Short-cycled)
No
(Not short-cycled)
Yes
(Dirty)
No
(Not dirty)
Yes
No
Clean the filter.
Wash the indoor heat exchanger.
Resolve the short cycle.
Wash the outdoor heat exchanger.
Check and repair piping.
Chart 2 of 4