Troubleshooting strange furnace noises and sounds

It's late at night on a cold evening here in Albuquerque. Suddenly, you hear a screeching coming from your attic or basement. Unless you have some kind of bat infestation (hopefully not!), chances are that what you're hearing is your furnace. Strange furnace noises are one of the main signs you need heating repair.Furnaces generally aren't noisy, and most modern furnaces are designed for noise reduction. A properly functioning furnace shouldn't make too much noise, especially after initially starting. One that is generally needs repairs, and the type of sound you're hearing can help determine the exact issue with the system.In this article, we'll run through some of the most common furnace sounds, and what they may signify. If you're hearing any of these—or you're unsure about what you're hearing coming from your furnace—contact the pros at Wagner. We'll inspect your furnace and determine the exact issue.

Four strange furnace noises (and what to do when you hear them)

Here are four common, but weird, furnace noises, and the most probable reasons for the sounds. Keep in mind that every furnace is different, so the only way to be 100% sure about the state of your furnace is to have the team at Wagner inspect your system.

1. Scraping noises

A scraping noise most likely means that there's a fault in the blower wheel of the furnace. This noise will sound like metal parts rubbing together, or nails scratching a chalkboard. Yeah, it's not fun.You'll want to call a furnace technician as soon as possible when you hear a scraping noise, and not just because it's obnoxious: this sound could indicate issues that lead to significantly higher wear-and-tear on your system.The blower wheel can be making the scraping noise for different reasons. The wheel may have become loose and is making the noise by hitting the blower casing. Having one of our techs tighten the blower wheel can often resolve this problem.Sometimes, a broken blower wheel can also be the source of this distinct noise. Moreover, the motor mount may have broken causing the blower assembly to hit the housing.

2. Screeching noises

A screeching noise that comes from the furnace is most probably due to motor bearing problems. (Here's what this sounds like)The motor bearing issue can be solved by one of our technicians strategically adding lubricant. This is something that you'll want a professional to assist you with: your standard WD-40 is too lightweight to be used here. We have a special lubricant that will stand up to the wear-and-tear of the furnace.Another common cause of screeching sounds? A bad belt. You must have a technician replace the belt immediately, otherwise the blower will no longer run and you'll be without heat.

3. "Thwapping" Sound

A "thwapping" sound indicates that something is stuck in the blades of the blower. Moreover, this sound can also be heard when something is stuck inside the housing of the furnace. The sound is similar to the noise made by playing cards when they are attached to the spokes of a bicycle wheel.Even if you can stand the noise, you should get the unit checked by one of our techs to get the problem resolved. Not taking any action can cause strain on the motor, resulting in a major system breakdown down the road.

4. Banging or popping noises

Banging or popping sounds are very common. Most of the time, these noises come from the air ducts as they expand and contract. These are pretty harmless. However, be on the listen for much louder banging or popping sounds. They could indicate issues with combustion in the furnace.For example, loud, repeating pops could be caused by too much gas being in the chamber when the furnace ignites, leading to a (very small) explosion beyond that of the normal combustion process. This can put stress on all parts of the furnace, including the surrounding metal.

When you hear strange furnace noises, call in the experts

Wagner is your source for heating repair services in Albuquerque and Santa Fe, New Mexico. Our dedicated techs work with all makes and models, and we offer 24/7 repair services.No matter what strange furnace noises you're hearing, give us a call today for an inspection.