Why is my furnace making funny noises?

Feb 26, 2021 | HVAC

Does the heating system in your Franklin County area home make “funny noises?” If so, you’re in the right place.

No one likes a noisy furnace. And while some sounds are normal and harmless, some aren’t. Some furnace sounds are a sure sign of danger.

As a homeowner, it’s important to know the difference because there are some noises that should be looked at by an NATE-certified furnace technician. 

To help you recognize the difference, we at Westerville Air Conditioning & Heating present the following:

Humming Sounds

If you have humming noises and they’re originating from your furnace, it might be from a defective starting capacitor or some other issue relating to the motor itself. If this isn’t addressed by an expert, it could progress into a blown motor. Having said that, remember you should hear a faint humming sound coming from your furnace while it’s still new. We are referring to humming that’s louder than the normal motor hum.

Screeching or Squealing

Screeching or squealing noises that seem off and remind you of nails on a chalkboard, or metal scratching loudly, could indicate the furnace’s blower wheel is having issues. 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.

Popping and/or Banging

Some banging and/or popping noises are normal with HVAC systems that utilize ductwork to transport treated air, which is most of them. Because air ducts are made out of sheet metal, they contract and expand when they get hot or cold air blowing through them. However, if a homeowner notices excessively loud or obviously new popping or banging noises and your home isn’t getting the heated air or cooled air you are accustomed to, 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 continues escaping, it can build up and lead to 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.

Smacking or Thwapping

Smacking sounds similar to a playing card flapping against a bicycle spoke, or “thwapping” noises, or s 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 Westerville Air Conditioning & Heating today at 614-810-0075, or schedule an appointment now by clicking here!