Not Heating – Window Wall Air-Conditioner
Issue
Unit not heating room very well while air is flowing through air conditioner.
Heating operation stops suddenly.
Applies to
- Westinghouse Window Wall Air Conditioner
- Kelvinator Window Wall Air Conditioner
Solution
Possible Causes and Solutions:
The air conditioner draws heat from the outdoor unit and releases it via the indoor unit during heating operation. When the outdoor temperature falls, heat drawn in by the air conditioner decreases accordingly. At the same time, heat loading of the air conditioner increases due to larger difference between indoor and outdoor temperature. If a comfortable temperature can’t be achieved by the air conditioner, we suggest you use a supplementary heating device.
Operating Temperatures.
Optimum performance will be achieved within these operating temperatures.
If air conditioner is used outside of the above conditions, certain safety protection features might come into operation and cause the unit to function abnormally.

Inappropriate temperature setting:
Set temperature correctly
HEAT Mode
- Press the MODE button to select HEAT mode.
- Set your desired temperature using the TEMP or TEMP button.
- Press FAN button to select the fan speed: AUTO, LOW, MED or HIGH.
- Press the ON/OFF button to start the unit.
For detailed method please refer to “HOW TO USE THE REMOTE CONTROLLER” section of the user manual.
De-Ice control has been activated:
In HEAT mode, the unit temporarily stops for maximum of 10 minutes to perform the automatic defrosting operation
Frost may be generated on the outdoor unit during heat cycle when outdoor temperature is low and humidity is high the air conditioner:
- During this condition air conditioner will stop heating operation and start defrosting automatically.
- The time to defrost may vary from 4 to 10 minutes according to the outdoor temperature and the amount of frost built up on the outdoor unit
Note: This De-ice control can happen more frequently with temperatures below 5ºC.
Compressor 3 minutes protection has been activated.
• The compressor can’t restart for 3-4 minutes after it stops.
Air Filter is blocked – Check and Clean air filter
Doors or Windows are open – Close doors and windows