Lennox LI018CI-180P432 Service Manual page 46

Service Manual
4. Communication malfunction E6
Cut off power supply. Check if
connection line of IDU and ODU
and the wire inside electric box
are correctly connected.
Main board matches
with display board? Main board of
IDU matches with that of ODU?
Communication cord is damaged?
Installation and Maintenance
Start
no
Correct connection?
yes
yes
no
Replace IDU's
main board
no
Malfunction eliminated?
yes
End
Connect the line
according to
wiring diagram.
no
Match correctly
no
according to product
specification
no
Replace
yes
communication
cord
no
Replace ODU's
main board.
Malfunction eliminated?
yes
Malfunction eliminated?
yes
Malfunction eliminated?
yes
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