It can be alarming when your HVAC system makes a sound that you are unfamiliar with. After all, we rely on these systems to keep our homes comfortable, so if there is a mysterious sound that indicates that there is a potential issue with them, it can definitely be worrisome. This is especially true if you are unfamiliar with the kinds of sounds that match up with different sorts of potential issues, so you have no way of knowing if you have a big problem on your hands.

Let’s look at all the sounds that an HVAC system makes when it is having an issue and just what kind of problem each sound points to.

When There Is a Thwapping Sound

A thwapping sound is similar to a card that is in the spokes of a bicycle tire. When you hear your HVAC system making this sound, it is typically indicative of something interfering with the blower blades. For example, some kind of foreign object got stuck or a blade became bent. Compared to some other sounds that you might hear, thwapping is not a major cause for concern. It can, however, lead to a belt or motor wearing down quicker than it would otherwise. This could make a motor work harder, giving you less energy efficiency. It could also lead to worse problems, so even though it is not a major issue on its own, it should not be ignored. Have a professional take a look at it as soon as you are able, but it is not an emergency.

When There Is a Clicking Sound

It is completely normal to hear a clicking sound when you start the furnace. If the clicking continues, however, this signals that there is likely a problem. Repeated clicking most often means that there is an issue with the ignition system. The inability of your system to start up during this clicking sound is a good indicator that it is indeed the ignitor system. This could be due to dirty burners, damaged flame sensors, a defective ignition board, or a defective valve. A persistent clicking sound could also be attributable to something other than the ignition system. A faulty fan motor or issues with the compressor or control panel could also be the issue. If you run into persistent clicking when you try to turn on your HVAC system, leave it turned off and immediately call in a professional to inspect it.

When You Hear a Rumbling Sound

When an HVAC system completes its cycle, it is normal to hear a woosh or roar. If the sound that you hear is a loud rumble, however, this could be a serious problem. A loud rumbling sound happens when fuel is burning in the combustion chamber, even after the system is turned off. This should be dealt with immediately by an experienced technician.

What Does Humming or Buzzing Mean?

A low humming or buzzing sound is typical and not really a cause for alarm. If it gets loud, this could be loose parts, a refrigerant leak, an out-of-balance motor, or even just an air filter needing to be changed. A humming sound might also point to an issue with a strained compressor or a motor going bad. With such a wide range of possibilities that a sound like this can point to, it is important to have a professional check out your system to pinpoint exactly what the issue is.

Banging, Thumping, and Rattling

A banging, thumping, or rattling sound can happen from a variety of different causes. It could be due to something that has come loose in the motor or blower. There could also possibly be a ductwork issue. It could also happen due to a dirty burner. Rattling, in particular, could be from something as serious as a crack in the heat exchanger, which could potentially leak carbon monoxide into your home. You will definitely want to shut down your system and have this issue immediately checked out.

What Does It Mean if There Is Screeching or Squealing?

When you hear a screeching or squealing sound, you are generally going to have a bad motor bearing or a belt going wrong. Sometimes this can be addressed by having the parts lubricated. If the belt breaks, however, this will lead to your system completely stopping. If you hear a screeching or squealing sound, have a professional check the belts and bearings for the need for lubrication or to prevent the belt from breaking before the system malfunctions.

What Does a Hissing Noise Mean?

If you hear a hissing noise coming from your HVAC system, especially after it is already turned off, this could indicate that you have an internal valve leak, the pressure from the compressor is too high, or you have a leaky refrigerant line. Another possible reason for the hissing sound is that your ducts could be leaking air. If you have leaking air ducts, it could result in a major increase in energy costs. This is because your system is having to overwork to compensate for the air that is being lost. Leaky ducts can also contribute to decreased air quality in your home, air filters getting clogged quickly, and inconsistent temperature regulation throughout the home. If you are hearing a hissing noise, you should have a technician have a look at your HVAC system.

Have a Professional Investigate the Sound

If you are experiencing a questionable noise coming from your HVAC system and are in Bountiful, UT or the surrounding area, it is best to have it checked out by one of our technicians at Blue Best Heating & Air. Hopefully, going through the potential causes of various sounds has at least pointed you in the right direction as to which sounds indicate that you are still likely safe to run your system and which ones point to an emergency where you should shut down your system immediately. We are a women-owned and -operated HVAC company that understands the concern that comes with hearing strange sounds from your system, and we are ready to help address the problem.

Blue Best Heating & Air has been providing high-quality heating and air conditioning services to folks for over 20 years. In that time, our team has amassed an exceptional amount of industry experience, which makes us well-suited to provide you with top-quality work and customer service. Not only can we repair the issue that is causing sounds in your HVAC system, but we also offer a full range of heating and cooling services and products. We can be there for you anytime you need a new HVAC system for your home or business, a tune-up, or an urgent repair. Our company is up-to-date with the latest in energy-efficiency technology and specializes in ductless repairs and installations. You can even come to us for an indoor air quality inspection. If you are ready to see what our team at Blue Best Heating & Air can do for you, give us a call today.

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