If your AC’s fan is running but not cooling, take the following steps:
- Check whether the air conditioner is not starting at all. See above to solve that.
- Check whether the thermostat knob is turned to the proper setting or cold setting on the electronic controller.
- Check whether the compressor is running. It is located inside the air conditioner.
If the compressor is running but it is emitting a continuous, humming noise without any cooling then there may be a problem with the moving parts such as the compressor, condenser or evaporator. - If the compressor is not running but you have a power supply to the air conditioner, then there may be a problem with one or more of the parts like the compressor, overload or relay thermostat (open thermostat), burnt wiring, bad selector switch, capacitor or electronic controller.
Such parts are not user-serviceable.