Why Is My Furnace So Loud?

There are many reasons your furnace may be making unusual noises as it operates. Even a newer furnace may be louder than it should be, so it’s important to have the heating system inspected by a professional. An HVAC technician can tell you which underlying issue is causing your furnace to produce loud noises.

A Failing Blower Motor

The blower motor drives the furnace fan that pushes heated air to your ducts and out into your home. The bearings in the motor must be kept lubricated, which is typically done during a seasonal inspection or tune-up. If the bearings aren’t kept lubricated, the motor may seize up, and that will cause the loud knocking noises you keep hearing.

If your fan makes a loud rattling sound when it kicks on, the motor may need lubrication. A furnace motor needs a particular type of lubrication, which is why you should call a professional to fix this problem. Your HVAC technician will know how to quiet a noisy furnace blower. If the motor has already seized up, your technician can help you explore repair solutions.

Furnace Makes a Squealing Sound When Running

Another reason you might ask, “Why is my furnace so loud?” may have to do with the belts that help the motor drive the blower fan. If these belts become worn over time, or if they lack the proper tension, they will make a loud squealing noise all of a sudden. If you ignore this problem for too long, the belt will break or snap. This will leave you with a furnace that isn’t blowing any air. 

Your HVAC technician can replace the belt with one of better quality before the belt breaks. They will also tighten the belt to ensure the tension is sufficient to eliminate the squealing noise. While this is a minor adjustment, it can help you heat your home quietly and more efficiently.

The Fan Causes Scraping Sounds

If you hear sounds of metal scraping against metal, this sound most likely indicates a loose or damaged blower fan. You might also notice that your heating system isn’t pushing out as much air as it should when it cycles. When the fan’s blades become dented or the fan gets loose, it will scrape against the sides of the housing.

Rather than causing more damage, you should stop using your furnace as soon as you notice this issue. If the fan is only loose, your HVAC technician may just need to tighten the fan and lubricate the motor. Even if the fan needs to be replaced, you’ll prevent damage to other components by waiting for the replacement fan.

Your Gas Furnace Starts with a Bang

If your furnace produces a loud bang when it turns on, your system’s burners may be clogged or dirty. When the burners develop these blockages, the ignition is delayed and gas builds up in the chamber. As the furnace ignites, the release of that built-up gas causes a small explosion. 

It’s important to schedule service for this issue as soon as possible. A delay will cause more sediment to build up in the burners. As a result, the delays will be longer and lead to a greater buildup of gas. Your HVAC specialist can clean the burners and ensure gas flows more smoothly.

Pay Close Attention to that Rattling Sound

If you hear a rattling sound coming from your heating system, you should contact your HVAC technician. Make sure to ask them, “Why is my furnace so loud?” When they have all of the information, they will be able to diagnose the problem for you. In many cases, this may just indicate screws that need to be tightened. However, it can also indicate a more serious problem, such as a cracked heat exchanger.

The heat exchanger will crack if the airflow is inhibited in any gas or electric furnace. When there’s insufficient airflow, heat will build up in the exchanger until it ultimately cracks. This is an important issue to have repaired since a faulty exchanger will cause the system to leak carbon monoxide into the home.

Your Furnace Sounds Like a Jet Engine

Whether you have an old heating system, or you’re wondering, “Why is my new furnace so loud?” it’s important to have the problem addressed by an experienced technician. A loud whistling sound that grows louder with continued use can be the result of a dirty air filter or something more serious. 

Especially if your new furnace is louder than old ones you used to have, a worsening noise should be addressed immediately. It’s better to stop using the system until it can be checked out to prevent the underlying cause from progressing. Your furnace may only need service and maintenance to eliminate the noise.  If you do need repairs, your technician will discuss your options with you.

Turn to the Team You Can Trust

Whether you need maintenance, repairs, or a new HVAC installation, contact TSS Home Comfort. We will help you find the best heating and cooling options for your home with options that will fit your budget. Call us to schedule an HVAC evaluation today.