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12-4. Air conditioner operates, but abnormalities are observed.
12-4-1.Operation does not switch from HEAT to COOL (or COOL to HEAT).
• Indoor PCB Ass'y is defective.
• Check voltage between terminals
No. 3(+) and No. 5 at 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 switch Ass'y may be
defective.
COOL
➞
HEAT
• Check voltage between terminals
No. 3(+) and No. 5 at terminal plate.
(0V)
HEAT
➞
COOL
If unit A is stopped, unit B will switch to cooling or drying operation.
(Example)
Unit A in heating mode
Unit B in cooling or drying mode
Unit A in heating mode
(Heating operation takes precedence.)
Unit B fan operating
• If the units are operated in different modes (for example, unit A in the heating mode and unit B in the cooling or
drying mode), the results are as follows.
Units A and B cannot be operated in different modes simultaneously (for example,
unit A operating in the heating mode while unit B is operating in the cooling or
drying mode). When operating two units at the same time, set them both to the
same mode. Note however that though technically different modes, unit A can
operate in the cooling mode while B is operating in the drying mode.
CAUTION
