Possible Reasons Why Your Air Conditioner Is Rattling

Posted on: 27 June 2017

One common problem you may encounter with your air conditioner is the development of an annoying rattling sound. Sometimes, this isn't a sign of anything serious, so you may be able to fix the problem yourself. Other times, it could mean a problem with the parts that needs to be looked at by an HVAC contractor. Here are some of the possible causes of air conditioner rattling.

Small Rock In The Cage

If the condenser isn't maintained properly, then debris can get blown inside or knocked inside by a mower. Anything from twigs to small gravel can end up inside the condenser cage and lodge in the moving parts of the AC. If it's something hard like a rock, it will make a rattling sound as it gets knocked around when the air conditioner is in operation.

Broken Or Loose Internal Parts

A consequence of debris flying around the condenser is that it can damage the fan or motor. When the fan has something lodged in it or when a blade is bent, it makes a rattling noise. The motor makes noises too if pieces of it are knocked off so they rattle inside when the air conditioner kicks on. It's also possible the mounts that hold the motor have vibrated loose allowing the part to shake and rattle. Problems like this need to be checked and repaired by an HVAC contractor right away before damage is done to the AC unit.

Loose Screws In The Panel Or Cage

If the air conditioner isn't screwed together tightly, it will rattle when the air conditioner kicks on. Screws can sometimes work loose when they're not seated tightly after performing maintenance or repairs on the air conditioner. If the noise is coming from the condenser outside, check the screws in the cage to make sure they are nice and tight. If the noise is coming from the inside unit, tighten all the screws on the panel to make sure the panels are seated properly. Also, check that all the screws are accounted for. Sometimes a screw can fall out completely and rattle around inside the air conditioner every time it turns on.

Also, check the condenser to make sure it is clear from debris on the outside. The rattling may be coming from a lawn chair propped against the side or from something sitting on top of the cage. If you can't locate the source of the annoying noise, call a contractor right away so you can be sure no damage is being done to your HVAC system by running your noisy AC.