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5 Reasons Why Your Furnace is Making a Loud Noise

furnace is making loud noise

It can be frightening when you turn on your furnace and hear a scary loud sound: That sound is not something to ignore.

Engineers design modern furnaces to operate quietly, so if it sounds like yours is a monster in the closet, it often means there’s an issue with your furnace. Depending on the noise, the problem in your furnace may be a monster to handle after all. Noises can be warning signs of greater issues that can be dangerous for your furnace and home.

The HVAC technicians at Cardinal will know the cause and solution to a weird noise. However, you can use this list to troubleshoot at home.

Common Furnace Noises

Furnaces can Contact a reliable technician if you hear any of these concerning noises below:

  • High pitched whistling 
  • Shaking or rattling
  • Groaning or booming
  • Scraping or Screeching
  • Buzzing or humming

1. The Blower Motor

Issue Sounds like Buzzing and Humming

The blower motor in your furnace exists to keep warm air circulating in a home. When a motor isn’t lubricated enough, it can begin to scrape and make a humming or buzzing noise. Sometimes this is the warning sign for a motor failure.

When the furnace motor gets clogged with dust and debris, it can be an amperage issue and kill the motor. To keep the motor free of amperage issues, change the air filters often.

If you hear buzzing when starting up the heating cycle, it’s necessary to enlist some professional help. 

2. The Transformer

Issue Sounds like Humming

The transformer has no moving parts and converts energy to keep the system running at the correct voltage capacity. If your furnace’s transformer begins to fail, it may begin to make an electrical buzzing noise. 

When a transformer makes this noise, it’s time to replace the hardware. If the transformer fully fails, you won’t be able to use your furnace.

If the transformer box is loose, it can rattle, creating a humming noise. If you’ve just had a new furnace installed, it may be possible that you need to tighten the mount up a little more. This solution is an easy task; you need a screwdriver to tighten the screws holding the transformer box up. If the noise continues, it might be time to call a professional.

3. Loose Equipment or Ductwork

The issue sounds like Vibrating or humming.

Over time equipment can loosen and begin to vibrate against each other. When this happens, one should tighten screws, nuts, bolts, joints and seams, or loose equipment can damage your furnace. Loose seams or joints can be a nasty problem in the ductwork because it causes inefficiency when maintaining temperatures in residence. 

If your ductwork is easily accessible, you may be able to tighten your ductwork using foil tape and mastic sealant.

If you cannot find the noise source or can’t access your ductwork, it’s time to call in professional HVAC assistance. Secure equipment will ensure that there are no air leaks or vibrating pieces.

If the vibration continues, areas of your ductwork could collapse, not to mention the higher utility bills due to wasted energy.

4. The Capacitor

Issue Sounds like Buzzing

It’s not abnormal to hear a dull hum when your furnace is running, but if the hum is too loud or the furnace is not responding to the thermostat, that sound usually represents an electrical problem. The furnace may turn on and make noise but will not run. 

A capacitor stores electricity to help give the furnace a boost as it begins a heating cycle. If the motor is not working, the buzzing noise may be coming from a failed capacitor. Schedule service with an HVAC professional to replace or repair the motor. 

5. Dirty Furnace Filter or Burner

Sounds Like whistling or banging

One of the scariest noises is a high-pitched whistling noise. This sound may mean that the furnace is clogged, and air can’t get through the dust, dirt and other debris. 

A dirty filter is often the easiest problem to solve because solving this problem only requires a fresh filter. Either clean the permanent filter or replace it with a new disposable one. It might be better to take the filter out altogether if you can’t make it to the store just yet to keep from overworking your furnace.

Filters should be changed or cleaned every 1-3 months to prevent issues like this.

If the burner is dirty, it will make a booming sound after the furnace starts up. If it sounds bad, that’s because it’s a signal for some bad news. Dirty burners delay ignition and allow gas to build up in the combustion chamber. The gas build-up can create an explosion and cause damage to the furnace.

If the burners are dirty, call an HVAC professional to come to repair them for you.

Find Professional Furnace Maintenance in Ashburn, VA Now

Your furnace never makes noises for no reason, so it’s important to act fast when it starts to sound like a monster. This list will be able to assist you in finding the cause of the problem, but we are here to assist you even further.

Call Cardinal HVAC and plumbing today to get a full inspection and full service for any noises you might be hearing from your furnace. Our team is knowledgeable, prompt, and reliable for any maintenance or repair you may need. We can offer multiple solutions to ensure your home is warm and your furnace works safely.

To schedule service with us, get in contact with us here today.

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