Turbo Air TAS-09EH/O Service Manual page 36

4. when indoor fan mainline or feedback wire is off，the indoor lamp panel displays F4 code. After directly
insert it well，To restart the unit to recover normal .
（2） the indoor communication wire is
off.
Communication wire socket.
the indoor lamp panel displays F1 code.
Indoor fan mainline is off。
The relevant socket with indoor fan mainline
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