5 Reasons That Can Explain Why Your Furnace is Buzzing and Humming, along with applicable solutions.

furnace technician repairman

Do you hear intermittent or steady buzzing sounds emitting from your furnace? We can help you identify the source of, and solution to your dilemma.


Most homeowners agree that ambiguous sounds can usually be heard in and around certain parts of their home. Many strange sounds are harder to explain than others... if you hear strange buzzing or humming sounds coming from your furnace, there is likely a good reason for it.

Most outdated furnaces do not operate quietly, plain and simple. The only way to shush them is to buy or rent a new, up-to-date unit, while ensuring to properly maintain its filters. It is also recommended that homeowners regularly schedule cleanings and monitor their units' combustion chamber for cracks, or wear and tear.

If you are constantly hearing sounds emitting from your furnace, which began recently, then many Calgary and Ontario homeowners are in the same boat as you - asking a search engine “Why does my furnace make a buzzing sound?”

There are several rather common reasons that may explain the buzzing or humming noises emitting from your furnace - Read on for potential solutions to noisy heaters and more. Please don’t hesitate to give us a call for additional insights, to request repair services, or to buy or rent a new furnace, altogether.

central furnace in basement 1. Your Furnace’s electrical transformer may need replacing

If you are dealing with an incessant buzzing , or are hearing humming sounds emitting from your furnace that started recently, it may be easily resolved by replacing its old electrical transformer as soon as possible. Depending on the age of a given heating unit, having a repairman replace its electrical transformer may significantly reduce buzzing and humming sounds (notably in older units). Be advised that most older furnaces create some degree of humming or buzzing sound as a bi-product of the electrical current passing through the furnace’s transformer, and may not completely eliminate sound emissions. Allowing your heater to run with a damaged transformer may eventually cause your unit to stop working altogether, which is why we recommend having a professional inspect it for you as soon as possible.

  1. Furnace Motor Failure

“Why is my furnace suddenly making buzzing or humming sounds?” The reason may be attributed to your furnace’s motor, which may be experiencing imminent failure. If the sounds are emanating from your furnace's blower, the situation may worsen if the furnace is left to operate without maintenance or appropriate repairs. The risk of suffering from co2 poisoning also increases as a furnace continues to run with such a malfunction.

  1. Why Won’t My Furnace Cycle On or Off?

Many reasons may exist, such as a faulty motor or transformer. On the other hand, your furnace may just be switched off or unplugged. If you have checked all the plugs, Smart Home Works will find out the cause of your furnace’s problems and provide you with valuable maintenance and tips, while we are at it.

  1. Equipment’s Attachments Are Coming Loose

Your furnace is composed of many components including washers, screws, nuts, bolts, fans, belts and more. If your furnace has not been maintained for a long enough period of time, it may begin humming or buzzing as a result of its equipment becoming loose. If a screw, for example, begins to strip, the screw’s functionality will be comparable to that of a nail… In essence, a nail does not offer an effective solution for applications that require a screw. In effect, the various parts within your furnace should be inspected by a licensed HVAC technician in order to rule out faulty attachments, which are generally a very cost effective solution in terms of effectively repairing your central heating unit.
plenum furnace buzzing

  1. The Joints That Compose Your Duct work are Becoming Loose, or the unit's metal housing is badly positioned.

There is a considerable amount of thin sheet metal that composes your furnace system. Your home, whether it is in Toronto, Edmonton, Calgary, Hamilton, Whitby or anywhere else in Canada, likely consists of ducts that are also composed of thin sheet metal. As your furnace ages, some of the joints that connect your furnace’s sheet metal components may start to loosen and come undone, which will cause the parts that it holds together to vibrate against other parts, causing friction between your central heaters' metallic components. Seams that come apart will require professional maintenance in order reduce the noise emitting from the faulty joints or plenum (pictured above). A professional HVAC technician can identify and repair such problems, while also offering tips to prevent the problem from becoming a recurring annoyance, and possibly a financial burden.

At Smart Home Works, Ontario and Alberta’s go-to furnace technicians, we offer quality furnace repairs that homeowners in GTA and Calgary can confide in. Our friends and neighbours have many great experiences pertaining to the outstanding quality of our furnace install, maintenance and repair services. Contact us here