8-4. Air conditioner operates, but abnormalities are observed.
8-4-1. Operation does not switch from HEAT to COOL (or COOL to HEAT).
• Indoor PCB Ass'y is defective.
• Check voltage between terminals
No. 1(+) and No. 3 at the terminal
plate. (DC 24V)
No voltage appears.
Outdoor PCB Ass'y is defective.
OK
• Remote control unit may be defective.
• Measure resistance of 4–way valve's
winding.
Receiver in lamp Ass'y may be
defective.
COOL
➞
HEAT
• Check voltage between terminals
No. 1(+) and No. 3 at the terminal
plate. (0V)
HEAT
➞
COOL
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