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The Main Line’s Premier Service Provider

Since 1976

The Main Line’s Premier Service Provider

Since 1976

24-Hour Emergency Service



Michall Daimion Heating & Air Conditioning, Inc. Blog

Odd Furnace Sounds? Here’s What They May Mean


You never want to have a noisy heating system in your home. Modern furnaces are designed to run at minimum noise levels: you can expect to hear some clicking as the furnace starts up, the sound of the burners igniting, and the hum of the blower fan as it pushes air through the furnace and into the ductwork. You may also hear an occasional rattle from the metal ducts as they expand from the heat. Otherwise, your furnace will vanish into the general soundscape of winter in your home, something you barely notice.

When you do notice noises from the furnace, it’s usually a sign it needs heating repair in West Chester, PA. We’ve listed some of the more common warning noises you may hear from your furnace this season and their possible meanings. When in doubt, always call for professionals service. Furnaces are not appliances amateurs should ever attempt to repair.


If you hear a rattling noise, check to see that the panel to the furnace cabinet is properly shut and latched. (Yes, it’s sometimes that simple.) If the sound continues, it may be loose parts, such as screws and bolts, inside the blower assembly, or the blower wheels are coming loose. This problem will worsen into a much larger one if it isn’t corrected, so don’t hesitate to call for repairs.


A sudden, loud boom sound when the furnace is starting up indicates that unburned gas is building up before the burners ignite it. This could be due to a problem with the ignition system. It may also be the burners are dirty or have carbon particles on them, delaying them from igniting and allowing too much unburned gas to build up. Anything having to do with the gas flow in the furnace must be left to a professional.

Screeching and Grinding

Loud mechanical sounds like this are probably coming from one of the motors. Screeching is the noise of motor bearings wearing down. Technicians can replace these bearings, which will save the motor from burning out. The screeching sound … that’s probably a motor burning out, and it will need to be replaced.


Clicking at start-up is normal for a furnace. You don’t want to hear the furnace clicking at other times or clicking steadily. It can warn of a variety of problems. It might be dirt on the motor bearings or an early warning they are wearing out. It can point toward loose wiring in the control board or other electrical problems. It can be the ignition system struggling to start. It could be problems in the gas lines or with the gas valves. If you hear the sound after the blower shuts off, it may be coming from cracks in the heat exchanger—which is a serious trouble that can pose health hazards. Shut off the heater at the furnace switch and call our technicians. 

We have 24-hour emergency service available to ensure that you have your heating problems solved as soon as possible and your family can get back to enjoying a comfortable home.

Call The Main Line’s Premier Service Provider since 1976: Michall Daimion Heating & Air Conditioning, Inc.

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