Why Is My Furnace So Loud and How Do I Fix It?

You’re likely dealing with an extremely loud furnace if you’re reading this. A noisy furnace isn’t just annoying; it can also indicate a problem that must be addressed before it worsens. That is why you should take action as soon as possible.

Why Is My Furnace So Loud and How Do I Fix It

There are several possible causes of a loud furnace and some easy steps to help you figure out the problem and get your home running quietly again. However, the best you can do is to have a licensed professional take a look at your furnace to diagnose the issue and offer the best solution. 

Frequent Furnace Noises

Here are the most common noises you might hear coming from your furnace: 

  • Rattling
  • Booming
  • Humming
  • Banging
  • Scraping
  • Screeching

Common Causes of a Noisy Furnace And The Solutions

Read on to learn what could be causing the noise and how to fix it.

Dirty Burners

If you hear a loud boom or bang sound when you turn on your furnace, it could be caused by dirty burners. Dirty burners can delay the ignition, leading to gas buildup and a boom or explosion when igniting.

An unbalanced air-to-fuel ratio may also result in a boom or bang noise. This indicates that there’s too much air and not enough gas in the combustion process, which can lead to a gas build-up and a boom sound.

Thirdly, a boom or bang sound may also be due to the contraction and expansion of metal air ducts due to temperature changes. This is a harmless occurrence and usually doesn’t require any intervention.

To fix these issues, have a professional clean the burners and check the air-to-fuel ratio.

Blower Motor

Your furnace’s blower motor is responsible for circulating warm air throughout your home, so if it starts to make rattling or screeching noises, it may be in need of lubrication. If you can’t do it yourself, have a professional lubricate the blower motor fan bearings. Otherwise, the fan may seize up, leading to costly repairs.

If the blower motor doesn’t sound like it’s rattling or screeching but still seems loud, it might need to be adjusted so that it runs more quietly. Contact a professional to adjust the fan speed accordingly.

Faulty Heat Exchanger

Rattling or crackling noises coming from your furnace could be due to a faulty heat exchanger. This is an issue that needs immediate attention as it can cause carbon monoxide gas leakage in the home, which can lead to serious health hazards. Have a professional come and take a look at it right away.

A cracked heat exchanger usually occurs due to restricted airflow, which a clogged filter or dirty furnace coils and blowers can cause. Make sure you regularly check and replace your furnace filter to avoid this issue in the future.

Loose or Damaged Blower Belt

Does your furnace have a belt-driven motor? If so, you may hear a loud squealing sound when it turns on. This is most likely due to a loose or damaged blower belt that needs to be adjusted or replaced. Have a professional check the belt tension and replace it if necessary.

Dry moving parts like shaft bearings can also cause squealing noises. If this is the case, you’ll also need to have them lubricated. It is advisable to schedule regular maintenance with a professional to keep your furnace running optimally and avoid any serious damage.

Blower Wheel

A loud scraping or clanking sound from the blower wheel could indicate that the blower fan is loose and rubbing against the blower house casing. Generally, this involves removing the fan assembly and inspecting the wheel for any damage or wear and tear. If it is damaged, you will need a professional to replace it with a new one.


Loud noises coming from your furnace can be annoying and even alarming, but they usually don’t indicate a major issue. Most of the time, you must have a professional clean and lubricate your furnace or replace worn-out parts like blower belts or wheels. 

It’s also important to keep up with regular furnace maintenance and inspections. This is the best way to ensure that it runs smoothly and efficiently while helping you avoid more serious problems down the line. With proper care, your furnace should continue providing comfortable temperatures in your home for years to come.

Schedule Professional Furnace Maintenance With The Experts at Robert B. Payne

If you need help with your furnace, the team at Robert B. Payne is here to provide expert advice and service. Our technicians are highly trained in all aspects of furnace maintenance and repairs, so they can quickly identify and resolve any issues immediately. We also offer seasonal maintenance packages where we inspect and troubleshoot your system every year so that you can be sure your furnace is running properly and efficiently at all times. Contact us today at 540-373-5876 to schedule an appointment!