It’s important to know when your HVAC system is making strange noises. If you don’t, the problem may become worse or even lead to a breakdown in your home.

In this blog post, we’ll discuss some of the most common causes for sounds and offer tips on how you can prevent them from happening in the future. 

  1. Screeching or Squealing Noise

Screeching is usually caused by the fan blades rubbing against an obstruction in the blade’s path, such as dirt and dust, which has built upon them over time. When this happens, it can lead to the fan becoming unstable and starting to wobble.

This can result in the blades breaking off when they hit a solid surface, which will cause screeching or squealing sounds that are made worse by more vibrations.

Squeaking is usually caused by worn bearings inside the motor assembly of your AC unit’s rotating compressor parts, such as the shafts, pulleys, and belts.

This noise can become more noticeable when the motor starts turning at a slower speed with less torque.

hvac system repair
  1. Banging Noise

Banging noise from the HVAC system may be caused by an out-of-balance fan or a faulty motor bearing. This noise is usually a result of the fan hitting the housing or coming in contact with another part of the system.

This problem can often be fixed with simple adjustments, such as balancing weights on each side of the blades until they spin at the same speed.

  1. Rattling Noise

Rattling noise in the HVAC system may be due to a loose or defective fan belt. This is an easy fix and can often be remedied by tightening or replacing the belt with one that’s of better quality.

You can check this site for HVAC repair options. 

  1. Thwapping Noise

A thwapping noise is a sound you hear when your air conditioner’s compressor kicks in and out. This can happen if a valve isn’t positioned correctly or as it contracts with age.

It might also be caused by debris on the refrigerant lines, such as leaves and dirt. If this frequently happens while cooling season begins, have an HVAC technician check it out.

If you hear a thwapping noise often, and the problem isn’t identified, it could cause permanent damage to your air conditioner’s compressor or other parts of the system.

It’s best not to wait until this becomes too much for comfort before calling in someone who knows how to fix it.

  1. Constant Clicking Noise

The clicking noise is a sign of trouble and should be taken seriously because it could lead to the breakdown of your heating system. However, there are other warning signs that can alert you to problems before they get worse. These include:

  1. Buzzing Noise

Buzzing noises in your air conditioning system can be indicative of a problem that needs to be addressed. If this is not the case, it might just be an annoyance that could go away on its own, but you should still contact a professional and have them come out for safety reasons.

If the noise does not stop when you turn off the air, then it is likely that the problem lies with your compressor.

This noise will usually stop once you restart the unit, but if not, there could be an issue with the refrigerant or a leak in one of the pipes.

  1. Regular Popping Sounds

Regular popping sounds are usually the result of air pockets in the system. The fix is to increase the pressure so that it pushes out any remaining air pockets from inside your HVAC unit.

You can do this by spraying water or opening a window and turning off the fan for 15 minutes before closing it again. If your heating unit seems to be constantly popping, you may have a problem with the thermostat.

The thermostat is the device that regulates how much heat your HVAC unit pumps out and how quickly it heats up to a certain temperature.

If you have too high of a setting, or if your system has an issue with its sensor, then it will work harder than necessary. This can cause more noise from the unit because it is constantly working.

  1. High-Pitched Screaming Or Whistling Sound

If you hear a high-pitched sound, it could be an indication of something wrong with the fan.

Most often, this is caused by either dirt or debris that has been jammed up against the blades or inlet vane, causing some type of restriction which will cause vibration and ultimately noise. If there’s no blockage, then your fan may have a bearing failure, or the fan motor is faulty.

  1. Booming Noise

If your HVAC unit is making a booming noise, the issue could be due to one of these:

  1. Hissing Noise

If you hear a hissing noise with your air conditioner, this is likely the sound of refrigerant escaping, and it may be time to call for service.

This can happen over time as seals wear down or when a leak has developed in the system. Either way, don’t wait too long before calling an HVAC professional because this is an indication of a serious problem.

If you hear any other noise, be it a clicking sound or anything else, contact your HVAC service provider ASAP to find out what the cause may be and if there’s something that can be done about it.

You don’t want to wait too long before addressing these problems because the longer you wait, the more likely it is that they will get worse.


It is important to keep in mind that a noisy HVAC system can lead to premature wear and tear on the equipment, so it’s best to take care of any problem as soon as possible.

If you notice your unit making strange noises or having trouble regulating its temperature, turn off the power immediately and book an appointment with an experienced technician for help.