It's not uncommon for an air conditioning system to start making unusual noises. You may hear rattles, screeches, thuds, and whistles. These sounds indicate a part is worn or something is loose in the system. While you'll need to call an HVAC contractor, like United Heating Cooling and Plumbing Inc, for a specific diagnosis, there are some simple things you can check yourself. Here's what to do when your air conditioner starts making funny noises.
Check The Outer Panels
Although you probably can't tell it, your air conditioner vibrates when it's working. This vibration can cause screws to work loose on the panels. When a screw is loose, the panel will rattle slightly. Also, a screw can fall out completely and get inside your air conditioner and cause a rattling noise. First, shut off the power to your air conditioner and then check the panel screws. Give them a couple of turns to make sure they are tight. If a screw is missing, you can take off the outer panel and see if you can retrieve the screw and replace it.
Clean The Fins And Filter
There might be twigs or other debris caught in the fins of the outdoor cabinet. This can create a whistling or rattling sound. Clean out the fins with a vacuum or brush. Be very careful not to bend them because a bent fin will cause a rattling sound too. You can buy a fin brush at the hardware store to use for this purpose. It will also help straighten the fins if you need to fix one that is bent. It's also possible for debris to get sucked inside your outdoor unit and hit against the fan and make noise. If that's the case, you can remove the outer panel and clean out the cabinet. Check your filter while you're cleaning your AC too. If your filter is clogged, your AC might make a whistling sound as it struggles to pull air through it.
Check The Fan
While you have the outer panels off the cabinet, check your fan. Make sure there is no debris stuck on it or dirt accumulation that causes it to stick. Look for a bent blade too. If the fan is out of alignment or has a bent blade, it may hit against the side of the cabinet with each turn and make a clicking noise. Brush off the fan and manually straighten blades that are bent, and if that doesn't help, you'll need to have a contractor figure out why the fan is malfunctioning.
You don't have to handle any dangerous internal parts to make the above checks. It's not a good idea to remove the inner panel that covers the working parts of your air conditioner. Only take off the outer panel so you'll be safe. If cleaning and making minor adjustments don't work, then it's time to call in an air conditioning repair service. You could have a worn belt or parts that need to be lubricated. Just don't ignore unusual sounds. They are a sign something is wrong, and your AC might be damaged if it is allowed to run when it's not working properly.