Air Conditioner Operates, But Abnormalities Are Observed - Technibel GRV79R5VAA Technical Data & Service Manual

10-4. Air conditioner operates, but abnormalities are observed.

10-4-1. Operation does not switch from HEAT to COOL (or COOL to HEAT).
• Remote control unit may be defective.
• Measure resistance of 4–way valve's
winding.
COOL HEAT
• Check voltage between terminals
No. 1(+) and No. 3 at the terminal
plate.
• Indoor PCB Ass'y is defective.
HEAT COOL
• Check voltage between terminals
No. 1(+) and No. 3 at the terminal
plate.
OK
(DC 24V)
No voltage appears.
(0V)
Receiver in lamp Ass'y may be
defective.
Outdoor PCB Ass'y is defective.
65