Reasons Why Your Furnace Is Making Loud Noises

There are all sorts of things that can go wrong inside of a furnace. Here are some of the most common culprits behind a furnace making loud sounds.

• Loose fittings: Your furnace is made up of many tiny parts working together. Whenever a screw gets loose or an access panel is poorly tightened, these parts can start bumping against each other. When this happens, it often results in rattling or thumping sounds.

• Duct contracting: If your metal ductwork is being rapidly cooled and heated over and over, you will hear booming, thudding, or popping sounds. This happens because changes in temperature cause metal ducts to expand and contract. Depending on how your ductwork is constructed, these fluctuations cause parts to thump against each other.

• Poorly lubricated blower motor: Most of the noise you hear from a furnace's usual operation is simply the blower motor. The fan in the motor pushes air through your ductwork, causing a lot of noise. The noise gets far worse when you skip regular maintenance. Without lubrication, your fan and motor will make very loud screeching or rattling noises.

• Loose blower wheel: This typically happens when the blower fan is gradually jostled loose. When it moves out of alignment, it can start hitting the blower house casing, resulting in a scraping noise of metal against metal.

• Loose blower belt: It is fairly common for the blower belt on a fan to become loose. This can cause a squealing sound whenever the blower is running.

• Faulty heat exchanger: The heat exchanger helps a furnace to combust fuel, but if it isn't getting enough airflow, heat can build up. Over time, the chronically high heat can result in cracks and splinters. You may hear a rattling noise whenever your furnace runs.

• Dirty burners: If your furnace's burners are dirty, they will delay ignition. This delay results in a buildup of gas, so when the ignition finally starts, you hear a bang or boom.

When your furnace is being loud, it might be tempting to just roll your eyes and ignore it. However, this is never a good idea. Furnaces are meant to be fairly quiet. Any time your furnace is being super-loud, it means something is going wrong. Depending on the issue, you might face all sorts of serious problems.

Even if your noisy furnace is not actively dangerous, it will still be problematic. A noisy furnace is a furnace that is operating inefficiently. If you are hearing furnace noises all the time, you are also using too much energy for your heating. This can result in sky-high utility bills during the winter, and it is also a waste of fuel.

Sometimes, the problem with a noisy furnace is that it indicates more issues in the future. Issues like a loose blower belt start out as a minor annoyance, but over time, it works itself looser and looser, until your blower fan becomes inoperable. This can cause your furnace to quit working suddenly, right when it's especially chilly. Delaying repairs can also end up damaging parts so badly they need to be completely replaced. If you don't want to pay for emergency repairs and replacement parts, you need to address the issue right away.

In some situations, a loud furnace is more than just a danger to your wallet and your comfort. It can become a threat to you and your family as well. Furnaces are combustion appliances, so when something goes wrong, there is a major risk. Problems like delayed ignition can cause gas to build up to such high levels that you end up with an explosion or a fire. Other issues, like a loose exhaust pipe or faulty heat exchanger, can cause poisonous carbon monoxide to leak directly into the home.

Who do you call to fix a loud furnace?

Find your local HVAC company at synchrony.com/findacontractor and get a licensed technician to come look at your machine. If you're lucky, the technician can just perform regular maintenance and get your equipment running smoothly again.

How long does it take to fix a loud furnace?

Expect repairs to take anywhere from a few hours to a few days.

Should you repair or replace a loud furnace?

In some unfortunate situations, the cost of repairs can be too high for it to be worth it. A general rule of thumb is to see if the cost of furnace repairs is more than half the cost of getting a new furnace. In those cases, it can be a better idea to just get a new furnace.

For furnace repairs and other unexpected household expenses, Synchrony is here to help. Our financing options can help make it easier to handle purchases for your home. We partner with businesses to offer financing solutions on home improvement, household appliances, and more.