What Causes Squeaking Noises From An Air Conditioning Unit

Air conditioning units can squeak for different reasons. The reasons can vary from model to model. Some causes of squeaking include the amount of time the unit is used, the age of the unit, and maintenance habits. Whether you've got a little or a lot of squeaking coming from your AC unit, it's always a great idea to have a professional do an inspection and make any necessary repairs.

Some Units Squeak as They warm up

Some AC units squeak a little bit more than normal when they start up in the spring. If you haven't used your unit over the winter and you are hearing squeaking, it can take a few days for all the gears and parts to warm up.

While it's not ideal, some units do squeak a little bit even after they are warmed up. Some squeaking could be happening due to the age of the unit. Although your AC may be working efficiently, squeaking noises can be annoying. It is recommended that you get a professional to do an inspection of the AC unit to ensure nothing major is developing.

Older Units Have Belts

If you have an older model, you will almost certainly hear squeaking as the belts wear out. Newer models do not use belts, so you'll need to check the specifications of your AC to see if it was made before that major change became permanent in manufacturing.

Belts typically come loose and slip off with wear in older models. You will notice the squeaking both inside near your vents and outside on the compressor unit if this is the case.

Newer Units Have Direct-Drive Motors

The direct-drive motors on newer units operate with fans that rely on quality bearings. If your bearings have worn out, you will hear the squeaking outside as the fans struggle to operate.

It is essential that you do not attempt to replace these bearings yourself. When the bearings wear out, you will need a new motor on your unit. Trying to fix it yourself will significantly increase repair costs if you damage the compressor unit, which is common for most do-it-yourselfers trying to make this repair.

Quick Fixes in Between Repairs

If you are unable to get a professional to inspect your AC unit immediately, you may be able to do a quick fix to stop the squeaking temporarily. Try to put lubricant on any moving parts like the fan blower, belts, or motor shaft. This will ease the stress on the AC unit until you can get professional help.

Differences Between Indoor unit and Outdoor Unit Squeaking

The outdoor unit is prone to squeaking seasonally as the weather changes. Defrosting in areas that experience ice can be straining for AC units. Additionally, it is common to hear squeaking if you are just entering the warmer months if the coils haven't gotten a chance to heat up all the way.

The outdoor unit will also squeak if it is old and is breaking down. This can be due to many different things, including:

  • A broken motor
  • Worn-out belts
  • Compressor malfunctions
  • Worn bearings

Heavy Use May Cause Squeaking

AC units that are overworked can squeak often. Many people ease the strain on their AC unit by taking extra measures to dehumidify the building to remove moisture in the air. If you reduce humidity by using a dehumidifier, you can cut your AC unit's workload down significantly.

Compressor Gauge Malfunction

In some cases, the pressure gauge on the outdoor compressor unit that contains coils can fail to turn the unit off. Many experts recommend turning the unit off immediately and calling a repair professional if you hear the squeaking noise on the outside unit and it is prolonged or is accompanied by a squealing noise.

How to Get More Info When You Hear Strange Noises

AC units can make a range of unusual noises when they have problems. You may hear squeaking mixed in with whistling, odd rumbling, or clanging noises. As already mentioned, it’s common to have some minor squeaks when you start the unit in the spring. If instead of minor squeaking, you are met with more substantial noise, it's a good bet that your unit has developed some wear issues over the winter. You should have a professional look at your unit sooner rather than later.

If you think you hear a squeaking noise, the first thing experts recommend is to check the outside compressor for noise and the inside unit near the vents separately. You might hear squeaking in both places, but you may notice it in only one area. You will want to pinpoint where the squeaking noise is coming from, if possible. This will help the technician know where to start work.

Sustained squealing, thumping, rumbling, hissing, or other odd noises all have meaning when it comes to repairing your AC. If you hear some squeaking, you aren't usually in immediate danger. Although AC fires and explosions are not common, they are not unheard of. If you notice any smoke, loose wiring, blackened areas on the wiring insulation, or deterioration on the wiring insulation, you should turn off the AC unit and call a professional. Do the same if it seems that there could be debris inside that is an ignition risk, which is often accompanied by large amounts of leaves piled up around the AC unit. 

If you hear the squeaking noise alongside a rumbling, rattling, or a host of other noises, it's wise to turn off the unit and call a professional right away.

Identifying whether you should lubricate, turn the unit off, or wait and let it warm up is mostly dependent on whether the squeaking is from the indoor or outdoor unit. If the squeaking is outside, lubricating the motor via the lubrication ports may be a good short-term fix. 

Great Maintenance Keeps Your Unit Running

Squeaking units often need a motor repair. These aren't usually the kind of repairs to take on as a do-it-yourself project. It is always best to schedule maintenance with a skilled technician. Keeping up with a regular maintenance routine will prevent fans, bearings, belts, and gauges from wearing out during use. 

If your system is prone to overworking, you should contact our professionals. They can help you add dehumidifying equipment or do maintenance to reduce the strain on your system. You may also find that your unit is too small if it struggles to keep your home cool. In that case, our AC technicians can help you choose a larger unit or add mini-split systems to your building.

Revival Heating and Cooling can provide central AC unit installation, energy audits, repairs, and maintenance in the Vancouver, WA, and Portland, OR areas. We are proud to provide estimates for our customers, including comfort and efficiency upgrade costs. We can also help you find the right unit size for your building. 

Our services include ductwork upgrades, sealing services, ductless heat pump installation and repair, air sealing, insulation installation, window installation, air quality improvements, and conversions for those moving between an oil and a gas system. Call Revival Heating and Cooling in the Portland or Vancouver area today for more information!