Loud furnaces can disrupt the peace in your home, turning your otherwise cozy environment into a noisy, rather annoying and distracting place. Understanding the causes of furnace noise and how you can minimize the sounds are essential for maintaining a relaxing living space. With this article, I want to share insight into the common causes of noisy furnaces, share practical tips for reducing or eliminating the noise, as well as discussing when it’s time to call an HVAC repairman before any problems get worse.
Identifying the Loud Noises from Your Furnace
Some of the less desirable furnace brands are just noisy to begin with. There may be nothing you can do, since off brands and those with lesser reputation are just built with less stringent guidelines.
Banging or Booming: This may occur due to delayed ignition. Gas can build up in the combustion chamber and, when it ignites, produces a loud bang. This might be due to a clogged or dirty burner or gas pressure problems.
Shrieking or Squealing: These noises often indicate a problem with the inducer motor or blower motor. While it may just be out of adjustment, fixing it now can prevent further damage.
Scraping Sounds: These can be a sign of worn-out bearings or a loose blower wheel that is scraping inside the squirrel cage.
Buzzing and Rumbling: Loose parts in the furnace or the enclosure itself can cause vibration and result in buzzing or rumbling noises that happen every time your furnace is running.
Popping and Cracking Noises: These can happen when the blower motor sends warm air into cold air ducts, causing the metal to expand and make small cracking sounds.
Humming Sounds: A loud humming noise could signal a serious problem with the blower fan or capacitor. If the noise becomes noticeably loud, it’s important to turn off the unit and call a technician.
Common Causes of Loud Furnace Noises
Age of the Furnace: Older furnaces often become noisier due to wear and tear on their components. Unless you’re ready to replace your furnace, there may not be much you can do about this specific reason.
Loose or Faulty Parts: Loose panels, screws, or internal components can lead to rattling or humming sounds that will persist until they are tightened. The front cover of my furnace doesn’t fit exactly right and it shakes every time the furnace starts.
Ductwork Issues: Expanding and contracting ducts can create popping or banging sounds. You can try to eliminate this with insulation around the duct or by using flexible duct instead of sheet metal.
Blower Motor Problems: If your blower motor is squealing or making scraping noises, it either needs to be replaced or re-aligned in the furnace to stop the scraping. There is a small set-screw that holds the motor to the squirrel cage itself and it can come loose over time, allowing the wheel to get off center.
Dirty or Clogged Filters: Restricted airflow can lead to increased noise levels and you may hear slight whistling noises every time the furnace is running. Try getting a new filter, or getting a better quality filter.
Tips for Minimizing Furnace Noise
It all starts by installing a quality brand furnace. Believe me, this is not one area you want to try and save a few dollars, since your furnace is going to last 15-20 years when maintained properly. Learn more about how quality and how it affects the cost of a furnace.
Regular Furnace Maintenance: Routine inspections and annual maintenance can prevent many noise issues before they start.
Tightening Loose Parts: Regularly check for and tighten any loose components like panels, screws, and belts.
Insulating Ductwork: Adding insulation around ductwork can reduce the noise caused by thermal expansion and contraction.
Lubricating Moving Parts: Keeping moving parts lubricated helps reduce friction and associated noise.
Cleaning and Replacing Filters: Ensure filters are clean and replace them regularly to maintain proper airflow. I write the date on the filter so it’s easily read through the filter grill. This helps assure they never go too long before being changed.
Upgrading to a Quieter Model: If your furnace is old and noisy, upgrading to a newer, quieter model may be the best solution. If you’re going to buy a new furnace, consider a high efficiency furnace to offset the cost and take advantage of tax credits while they last.
When to Call an HVAC Repairman
While some noise issues can be addressed yourself with DIY methods, there are several type of noises that signal you should call a professional
Unfamiliar Noises: If your furnace starts making unfamiliar sounds it’s time to call a professional before they get worse or the furnace fails completely.
Loud Banging or Popping: These sounds can indicate serious issues with your heat exchanger, ductwork or the furnace itself.
Persistent Rattling or Humming: If tightening components doesn’t resolve these noises, it could indicate a deeper mechanical issue.
Decreased Efficiency: If your furnace is noisier and your energy bills are higher, it could indicate a problem affecting efficiency.
In Closing
A noisy furnace not only disrupts the peace and quiet of your home but can also signal underlying issues that you need to address before they get worse. Regular maintenance and addressing minor problems quickly can significantly reduce noise levels and also prevent you from having to replace the unit when you didn’t plan on it. When noises persist or are accompanied by other signs of malfunction, it’s crucial that you consult an HVAC professional.
Ensuring your furnace operates quietly not only contributes to a more peaceful home environment but also enhances the efficiency and longevity of your heating system.