Is a Buzzing Furnace Dangerous?

The Consumer Product Safety Commission (CPSC) issued another warning in 2023 that urged Americans to be cautious when using furnaces and space heaters in their homes. Heating systems like furnaces and other heaters are among the most common causes of fires.

For this reason, proper maintenance and care of your heating system is crucial. Problems like a buzzing furnace are common issues that many people are unsure how to handle. But is a buzzing furnace dangerous? How do you know what to do?

You’ll need to keep reading this guide to learn everything you need to know about your furnace making a buzzing noise.

Is a Buzzing Furnace Dangerous?

A furnace buzzing can be dangerous and often indicates electrical issues with your furnace. If you leave it unchecked, it can result in increased air pressure or heat, leading to mechanical failures and fire.

Learning more about the most common causes is essential so you know what you’re dealing with.

Common causes include:

Loose or Malfunctioning Transformer Box

The transformer box is usually located inside your furnace, supplying the necessary power. The transformer controls the amount of voltage capacity and output. It’s responsible for the basic control of your furnace, like ignitions and timers.

Essentially, the transformer box alters the incoming volts and keeps your furnace working. If any part of the transformer becomes loose due to age or poor installation, it will begin to buzz when running.

You may also notice your furnace buzzing when turning it on.

Inadequate Blower Motor

Your furnace has a blower motor that distributes warm air through the ventilation system of your entire home. It does this after the furnace heats the air by forcing or blowing it through the ducts.

If the blower motor isn’t performing correctly, you’ll hear your furnace making a humming noise like a low buzz. You may also notice poor airflow from the vents with the buzzing sound.

The buzzing sound typically indicates the entire blower motor is failing. 

Loose Air Ducts

You may have loose ductwork if the buzzing noises come directly from your vents instead of the furnace.

High-pressure air that blows through the ventilation can loosen up parts of your HVAC and cause them to vibrate against other components.

This will cause a buzzing sound every time you run your furnace.

Faulty Capacitor

Buzzing furnace noises can also occur when you have a defective capacitor. The thermostat initiates the capacitor to begin your heat cycle. It does this by providing a steady flow of electricity.

If the capacitor is working normally, it shouldn’t make any noise. If it’s making a buzzing sound, it’s not regulating electricity normally.

Dirty Air Filter

Your air filter should be replaced every three months. A clogged air filter can cause your furnace to make a humming or buzzing sound.

This is because when air filters get clogged with dirt and debris, it causes your furnace to work even harder. As a result, your entire system may experience more vibrations causing buzzing and humming sounds.

Additionally, dirty air filters can cause health problems like worsening allergies, recurrent colds, coughing, sneezing, and asthma attacks.

Not only will you have a buzzing furnace, but you won’t feel well, either.

Low Pilot Light

Sometimes, you might notice your furnace buzzing when it’s off. This may sound like a low buzzing sound, usually due to your pilot light having the wrong adjustment.

Most of the time, it’s a low pilot light that needs adjusting. Once it’s adjusted to the appropriate level, the humming will stop.

What Should You Do if Your Furnace is Buzzing?

If you hear your furnace making a loud buzzing noise, you must immediately address the problem.

First, turn off your furnace and do not use it until the issue is addressed.

If your air filter is dirty, you should change that and see if it solves the problem. You can also vacuum around the ductwork if you notice clogs or other signs of buildup.

Call a Furnace Repair Service

Next, you should find a professional furnace repair service in your area. An experienced technician will be able to evaluate your system to figure out the problem.

Be sure to research to ensure the furnace repair service you use is a reputable company. It’s also a good idea to look for services like free inspections, A/C, and maintenance services.

This way, you can use the same company to keep both your heating and cooling systems running well all year.

Once they arrive, they’ll start with basic troubleshooting with the blower motor since it’s the most common cause. If it is the blower motor, the technician will ensure it’s cooled down and run some tests.

Sometimes the buzzing can be due to something simple like a lack of lubrication. Other times, you’ll need to replace the entire blower motor.

If this isn’t the issue, the technician will continue to run through various checks until they diagnose the problem.

Regular Inspections and Maintenance

Once your furnace is fixed, it’s essential to get regular inspections and maintenance done. Most professional companies have maintenance programs that offer various discounts.

Regular maintenance will prevent common furnace issues like:

  • Furnace water leaks
  • Carbon monoxide leaks
  • Furnace blowing cold air
  • High energy bills

It will also help ensure the air quality in your home is healthy. This is because maintenance includes a thorough cleaning that removes all dust and debris buildup. A technician will clean the furnace blower and flue pipes and check for leakage.

You’ll also decrease the risk of gas and carbon monoxide leaks since regular inspections ensure everything works properly.

Regular maintenance will also extend the life of your furnace overall. Catching minor problems early prevents expensive repairs.

It’s best to get regular inspections at least twice yearly, in the fall and spring.

Keeping Your Furnace From Buzzing

Is a buzzing furnace dangerous? Now that you know the answer to this question, you’ll feel much more comfortable dealing with this type of issue.

Don’t hesitate to call in the professionals. Although it will initially cost you, you’ll save money in the long run since your furnace will be working properly.

To learn more home tips and tricks, make sure to read the rest of our blog articles today!