Air Conditioner Operates, But Abnormalities Are Observed - Sanyo STW-2 Series Technical & Service Manual

7-4. Air conditioner operates, but abnormalities are observed.

7-4-1. Operation does not switch from HEAT to COOL (or COOL to HEAT).
(Only for heat pump model)
• Measure resistance of 4–way valve's
winding.
7-4-2. Poor cooling or heating.
• Measure temperature of suction and
discharge air of air conditioner.
• Check for clogging of air filter.
• Fan speed is set to LOW.
• Review cooling load estimate,
if performance of air conditioner is
normal.
7-4-3. Excessive cooling or heating.
• Set temperature is suitable.
OK
(SC)
Temperature
difference
is small.
Temperature difference between
suction and discharge air is
large enough (in cooling operation:
approx. 14 °F or more).
Air filter is clogged.
YES
NO
Check PCB Ass'y .
Possibility of
gas shortage.
Clean filter.
Set fan speed to HIGH.
Reduce cooling or heating
load or replace the air
conditioner with larger
capacity.
Set temperature to higher or
lower value using thermostat.
47
(Controller)
Charge refrigerant
gas (R22).