The temperatures are only going to get colder and we want to make sure that our furnace is running correctly. Many appliances make noises as they work that are normal but there are noises that a furnace shouldn’t make. The most common complaints with HVAC units are a noisy indoor unit, air handler or furnace. These noises typically fall into one of six categories.

Common Furnace Noises; Grinding, Buzzing, Rattling, Clicking, Knocking & More

1. Loud scraping, grinding metal hitting metal sound. If you hear this sound you need to turn the furnace off right away or you may face a costly repair bill-. This noise is the worst you will hear of the six we’ll talk about and can happen if the blower wheel has gotten loose from the motor shaft, has shifted and is hitting the housing of the blower. This can be corrected, providing the wheel hasn’t been damaged, can be moved into the right position and then re-tightened to the motor. This noise can also indicate that the blower wheel has broken and will need to be replaced. Another cause could be that the motor mount has broken, causing the whole motor and blower assembly the fall and the wheel will hit the housing.

2. Loud thumping, knocking or vibrating noise. This sound is like the one you’ll hear when your washing machine is out of balance. The cause is most likely an out of balance blower wheel or the motor has become unbalanced also. This sound is bearable but should not be ignored as it can cause other problems to the furnace.

3. Loud humming or buzzing noise. In this case, most often the transformer is noisy if the unit seems to be working correctly. Most transformers tend to hum but if the unit is not working and you do hear the hum, the indoor fan and/or capacitator might be bad.

4. Rumbling or clicking noises from furnace. This noise can happen with gas systems and can indicate a serious problem. This noise can indicate an issue with the burner portion of the unit. The unit needs to be turned off right away and you’ll need to call for help immediately.

5. Loud pop or bang sound from furnace. This is the noise you’ll hear when the system fan initially starts and/or stops and will only happen in systems that have sheet meatal ductwork. It usually happens with the return duct. The negative pressure of the fan will “pop in” the duct when the fan starts. When it shuts off, there is a release of pressure and the duct will “pop out”. This can happen if there is a clogged filter, closed vents, a flimsy duct or an undersized duct.

6. Rattling, squealing or high-pitched sound. This sound is usually related to heat pumps and usually means that there is a refrigerant-flow issue. It may be a check valve and may not be a problem. There are units that just have noisy check valves or metering devices. If you have checked the air filter and the sound becomes louder or annoying, a call for service is needed.

Furnace Inspections, Tune Ups, Emergency repairs, Replacements & More in Manhattan, Flushing, Queens, Brooklyn & The Bronx, New York

Make sure your furnace is ready for winter. Contact Agape Air Conditioning, Heating & Plumbing to schedule a furnace inspection and tune up today.