Check the circuit breakers on your main power distribution panel. Air conditioners generally only cool at one speed (though some have variable speed settings to improve energy efficiency). Mitsubishi 24000 Btu Mr Slim Tri-zone Ductless Mini Split Air Conditioner Heat Pump 208-230v 6 6 12 Ductless Mini Split Room Air Conditioner Air Conditioning Maintenance Changing the air filter regularly — seriously. Why is my air conditioner not cooling to set temperature . The filter is filled with dust and dirt. Air flows out but it does not cool or heat enough. If you can’t figure out the answer to “why is my air conditioning not cooling,” it could just be that the circuit breakers may have tripped. Contact with your installing contractor. If you see ice on your air conditioner in the middle of a hot summer day, you can rest assured that there is something amiss with your refrigerant. Lowering the temperature too much only makes your air conditioner run for longer, increasing wear an...