Why is my furnace making funny noises?

Feb 26, 2021 | Uncategorized

Is the heating system in your Clark County home making “funny noises?” If so, you’re in the right place.

Even though some furnace noises are normal and harmless, some aren’t. Some are sure signs of danger.

As a homeowner, it’s important to recognize the difference because certain noises should be looked at by an HVAC professional. 

To help homeowners know the difference, we at Springfield Heating & Cooling list several prevalent types of furnace noise a homeowner might hear and how regular maintenance can help them avoid expensive repairs.

Screeching Noises or Squealing Sounds

If you’re hearing screeching or squealing sounds that remind you of nails on a chalkboard, or metal scratching, and it’s coming from your HVAC equipment, it could mean your blower wheel is having problems. The wheel might have come loose from the motor shaft. Or, it may be broken or hitting against the sides of the system. In any case, screeching noises often indicate a bad belt or motor blower.

Banging or Popping Sounds

Mild banging sounds or popping noises are fairly normal with unit’s that utilize ductwork to transport treated air. Because air ducts are made from sheet metal, they contract and expand when they’re hot or cold. Nevertheless, if you are hearing excessively loud (louder than usual) popping or banging noises and your home isn’t getting the heated air or cooled air you need, there might be a problem with the system’s ignition. Sometimes, when a heating system’s burners are dirty, gas can escape into the unit’s housing. Because it won’t be able to light at the burner if it is escaping, this gas can build up and cause an explosion. 

In any case, this problem can be a highly dangerous one. If this is something your heating system is doing, please shut it down and call us without delay.


Humming noises coming from a heating system isn’t a normal sound and might be from a malfunctioning starting capacitor or some other issue having to do with the motor itself. If not addressed by a technician, this humming sound could get loud and then evolve into a blown motor. Keep in mind, you should hear a faint humming noise the day your system is installed. We are referring to anything louder than that.


If you hear a “thwapping” noise, or smacking sound that’s like a playing card flapping against a bicycle spoke, there’s probably something lodged or stuck in the blower’s blades. If this is the case and the object gets loose, it could go into the housing and damage something else.

Don’t allow strange sounds to go unchecked!

Residential heating systems are complex machines that are intricate; they utilize a whole host of parts and equipment, and they use fuel to generate heat. If you’re hearing any other unfamiliar sounds — thumping, squealing, rumbling, banging, loud whistling, etc. — it’s something you should take seriously. We suggest turning the unit off and giving us a call right away to avoid danger and further damage.

If your furnace is not heating properly and is making noises, call Springfield Heating & Cooling today at 937-350-1881, or schedule an appointment now by clicking here!

Also keep in mind, these are things that can be addressed ahead of time as part of a standard preventative maintenance appointment, which really should be done every year!

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