Gree Multi+ Ultra MULTIU18HP230V1DO Service & Parts Manual page 33

Service Manual
De-energize, check if the connection wire between
the outdoor mainboard and the filter board
according to the wiring diagram
Installation and Maintenance
All the indoor units appear
communication malfunction
De-energize,check the connection
wire of indoor and outdoor unit and
the wire of the eletric box is
connected correctly
Connected correctly?
Y
Connected correctly?
Y
The connection wire is broken?
N
Check if there is power input
bewtween the netrual wire and live
wire of the outdoor mainboard
There is power input?
Y
Replace the outdoor
mainboard
Resume communication?
Y
End
N
Reconnect according to
the wiring diagram
Reconnect according to
N
the wiring diagram
Y
Replace the
connection wire
N
Replace the filter board of
the outdoor unit
N
Replace indoor
mainboard
Eliminate the malfunction
Y
Eliminate the malfunction
N
Eliminate the malfunction
N
Y
Eliminate the malfunction
N
Y
Y
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