When you are a homeowner in Virginia, it is likely that you are going to need to run your furnace all through the colder months to keep your indoor temperature comfortable. That is why hearing your furnace make a strange sound is so alarming. What does the sound mean? Is it a problem that is going to cause your heating system to break down in the middle of the winter? Having these kinds of concerns is understandable, but not all sounds need to be a cause for major concern. Educating yourself on the types of sounds your furnace can make is very helpful in knowing what sounds are likely not too big of an issue and which ones should have you calling in a local HVAC professional immediately.

What Is the Scraping Noise You Are Hearing?

If you are hearing a scraping noise, there could be an issue with your blower wheel. The metal-on-metal scraping sound can be from the blower wheel becoming loose and coming into contact with the blower casing. There is also the possibility that the blower wheel is completely broken.

Should you encounter this type of sound, it is important that you turn off your system immediately and get in contact with a technician.

What Is the Screeching or Squealing Sound?

When there is a screeching or squealing sound, this generally points to a problem with the blower motor. In some cases, however, the sound you are hearing could be due to a broken belt. Turn off your system and contact an HVAC professional. If it turns out to be the blower motor, it may just be a matter of lubricating motor bearings that have dried out. If the sound winds up being from a broken belt, then the technician will install a belt replacement.

What Does It Mean if You Hear Popping or Banging?

When you hear popping or banging noises in your furnace, this is not immediately cause for concern. This sound can simply be from your ducts expanding and contracting. If these sounds get exceptionally frequent and loud, this could mean an actual problem. An issue with the ductwork could lead to loud popping or banging sounds. Another possibility is the burners becoming dirty, which can result in a delay in ignition. This could end up cracking the heat exchanger, which would be a costly repair. More important than that, a cracked heat exchanger could threaten the safety of you and your loved ones.

What Is a Whistling Sound in Your Furnace?

A whistling sound in your furnace is usually your blower motor, much like when you hear squealing or screeching. This is typically due to airflow issues, which could be remedied by opening all of the vents or changing the air filter. The whistling sound is likely stemming from the blower straining to draw in enough air for heating. A sound like this is not a major concern, but it should still be run past your HVAC technician.

When There Is a Rattling Sound

A rattling sound usually stems from there being a loose door or panel. This could be as simple of a fix as tightening any loose screws to ensure that all of the panels and doors that are outside of the furnace are fixed firmly. If this does not resolve the issue, then the rattling could be from a loose part that can be found by an HVAC technician.

There are rare occasions when rattling can be caused by a crack in the heat exchanger. If this is the case, dangerous amounts of carbon monoxide could be leaking into your home. If the problem is not a loose door or panel, turn off your system immediately to have a professional come out to check for loose parts or a cracked heat exchanger.

When You Hear Rumbling

There may be a slight whoosh or roar when your furnace completes a heating cycle. If you instead hear a rumbling sound, this could be a problem. A loud rumble could be from there being an issue with the burner. This typically comes from fuel continuing to burn in the combustion chamber after the burners are off. When you hear a loud rumbling, keep your system off and call a professional immediately.

What Does a Humming or Buzzing Sound Mean?

It is typical of most furnaces to emit a low-level humming or buzzing sound while in operation. If the sound is loud, however, there could be a problem with either the fan or the motor. You should have a technician look at your system right away.

What Does a Thwapping Sound Mean?

Thwapping is a sound much like a card in the spokes of a bicycle tire. This is usually caused by something interfering with the blower blades. An issue like this is not of immediate concern but should be inspected by a professional. A belt or motor can wear out more quickly if the problem is left unfixed. It could also lead to a decrease in efficiency and eventually a costly repair.

What the Clicking Sound You Hear Is

You may hear a clicking sound when you start up your furnace, which is the sound of the ignition system lighting the furnace. There is only a problem with this sound if you continue to hear it repeatedly throughout the heating cycle. You may also hear a repeated clicking sound while your furnace fails to ignite altogether. This can be due to dirty burners, damaged flame sensors, or a defective valve or ignition board.

Other possible reasons for the clicking sound are an issue with the control panel, fan motor, or compressor. Repeated clicking sounds should not be ignored and merit a swift call to a qualified HVAC technician.

Normal Sounds for a Furnace

Now that you know the sounds that indicate a problem, it is also important to be aware of the sounds that are part of normal operation.

Chirping Sounds

Chirping is typically just a natural noise that comes from the system’s mechanisms.

Short-Term Rattling Sounds

When there is short-term rattling as the system cools after a cooling cycle, this is not a cause for alarm.

Crackling Sounds

When metal components cool after the end of a heating cycle, this is a normal part of operation.

Pinging Sounds

This type of sound is also a normal occurrence when metal contracts within the duct system.

Speak to a Professional About the Weird Sounds You Are Hearing

If you are hearing unusual sounds, it is always worth erring on the side of caution and speaking to a professional about it. At Meade’s Heating and Air, we understand the importance of knowing that your furnace is working at its full potential and that you can continue to count on it for years to come. That is why we are ready to help with any unusual sounds you might be having and can also set you up with routine maintenance so that you can always feel confident about the integrity of your heating system. We also offer a full range of heating, cooling, and air quality services to Sterling, VA, and the surrounding area. This includes repairs, installations, and maintenance, all delivered with a dedication to world-class 21st-century customer service. If you are ready to experience the Meade’s Heating and Air difference, give us a call today.

Meade's Heating and Air

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