What’s That Sound Coming From My Furnace?

It’s normal for your furnace to make some noise. For instance, a dull hum is to be expected. However, louder noises might spell trouble for your heating unit’s components. Remember to turn off your furnace if it makes any alarming sounds and leave the repair job to a professional.

To help you, our Coastal Air + Refrigeration team here in Myrtle Beach made a list of six common furnace noises, what might be causing the noises, and what to do if you hear them.

1. Loud Banging

If you hear a loud banging noise, you should turn off your furnace right away. This might mean you have dirty burners that cause gas buildup in the ignition. A heating, ventilation, and air conditioning (HVAC) technician should clean your burners once a year during a maintenance inspection. 

Another culprit could be your vents expanding and contracting due to temperature change. No matter the cause, you should have one of our professionals inspect the problem right away. Internal equipment knocking around could lead to a cracked heat exchanger, which is grounds for replacing your furnace as stated by the American Gas Association.

2. Screeching

When your furnace is low on lubricant, this can produce a high-pitched screeching or squealing sound. The bearings and/or belts are squeaking and need to be oiled. It’s best to give one of our HVAC professionals a call, since you can’t lubricate your furnace sufficiently with common household oils.

3. Rhythmic Metallic Clanging

If your ears detect a clanging or thud repeating in a rhythmic fashion, there’s probably something caught in the blower blades. If you hear this noise, power down your furnace and inspect the blades to see if a foreign object has made its way into there. If you can’t see anything, give us a call to help.

4. Metal Scraping

When your blower fan comes loose, it scrapes against other metal components creating a shrill noise. In this case, you should turn off your furnace immediately to prevent further damage. If you catch it early on, the repair should be pretty simple and inexpensive. Leave it for too long, and the repair could be more serious.

5. Recurring Clicking Noise

This sound might be harder to pick up on, so you should pay careful attention. It might mean you have a defective relay switch, which is the component sending electricity to the heating parts and motor. 

Another possibility is your flame might be having trouble staying lit. A misaligned or dirty thermocouple can prevent the flame from staying lit. Or a bad gas valve could be the culprit. Either way, call one of our professionals as soon as possible to keep your furnace and North Carolina home in good condition.

6. Low-Pitched Growl

This is another sound you may not notice. It’s the sound of extra combustion occurring, which could be caused by dirty gas burners or a misplaced pilot light. No matter the cause, this scenario requires a professional’s attention.