What Does It Mean When Your Air Conditioner Pipes Freeze & Make Noise?

Outside Noise

• If the outside temperature is very low, this could cause an ice buildup problem for your air conditioner during operation. Outside air lower than the lowest thermostat setting on a running air conditioner causes moisture to accumulate inside the unit and freeze. Ice buildup prevents the unit from blowing air and might block the fan, which produces a noise every time the fan blades hit the ice.

Fan Housing

• A blocked fan causes the air conditioner unit to freeze and cease cold air production. While there are many reasons a condenser fan might stop turning, an improperly installed fan could produce ice buildup and an annoying noise. If the fan isn’t centered correctly within the unit, the fan blades will hit or scrape the fan housing. The fan housing prevents the fan from turning effectively, and moisture builds up in the unit and freezes on the cooling element. The clanking of the fan blades against the housing makes a metallic scraping noise. The fan can be removed from the housing and reinstalled properly, so that the blades spin freely.

Debris

• Sometimes unwanted or harmful items make their way inside of the air conditioner. The items are either sucked in through the intake grille or placed inside of the intake grille by children. This debris can wrap around the condenser fan during operation, prevent the fan from pushing out cold air and cause all kinds of noises. If the fan is unable to turn, the unit freezes and fails to cool. Front panels of the air conditioner unit can be removed to access the fan housing. All debris, such as plastic bags or sticks, should be removed from the fan motor.

Thermostat

• The condenser fan and internal compressor both stop functioning when the temperature in the room matches the thermostat setting. The condenser fan might still continue to circulate the air in the room after the thermostat setting is met, depending on the air conditioner setting. If the fan turns off but the compressor continues to run, the unit freezes over. The thermostat emits a slight noise when the signal to disengage is sent to the fan. If you hear the compressor continue on without the fan, the thermostat might be broken or disconnected from the internal compressor.