Why Is My Furnace So Loud?

On a cold winter evening, you’re sitting at home trying to relax. All of a sudden, you hear your furnace turn on, and it sounds like a jet engine. Today’s heating systems are designed to operate quietly, so if you have to ask yourself, “why is my furnace so loud?” or worse, “why is my new furnace so loud?” there’s a problem.  

Furnace Noises When Running 

If you’re listening for a problem with your furnace when it kicks on, you may hear the following noises: 

  • Banging or clanging 
  • Rattling or shaking 
  • Whistling
  • Loud humming

If you hear any of these sounds when your unit turns on, you need to schedule an appointment with an HVAC contractor. 

Why Is My Furnace So Loud? 

There are many possible causes for your furnace making loud noises. 

Gaps in Ductwork 

Any openings in your ductwork will produce a whistling sound you can hear. Whistling could also be coming from ducts that are too small for the air volume being sent through them. 

Clogged Filters 

A clogged filter will limit the airflow in your furnace. Does whistling stop when your furnace shuts off? If so, then replacing the filter may resolve the issue. 

Flexing Ductwork 

If the pressure changes between the return and supply ducts, the ductwork may bend or curve. This bending is known as oil-canning and happens because there is a weak spot in the ducts. It’s a serious problem that only a professional can fix.  

Loose Screws 

Some noises in your furnace may be caused by loose screws. Tightening them is a simple repair that you can attempt by using a screwdriver on the screws on the sides of the furnace. This tightening should solve the problem, but if not, contact a professional. 

How to Quiet a Noisy Furnace Blower

Your furnace is an intricate piece of equipment with moving components. If it’s making any strange noises, the best way to solve the problem is to contact the experts. A malfunctioning furnace can explode or burst into flames and lead to serious damage. 

A professional will know how to safely work with the equipment to repair it and prevent it from making too much noise. 

New Furnace Louder than the Old One 

There are many reasons why your new furnace may make more noise than your old furnace, but they are fairly simple. Older units had only a blower motor to regulate heat. 

If you have added air conditioning, your unit might work sufficiently when the AC is on, but not as well as a system designed to complete both functions.  

Your older system may have had a smaller design, including smaller ductwork. This setup makes it more challenging to get sufficient return air. Now, with a new unit requiring a greater demand, the ductwork might be rattling in response to the load it must carry. 

We Can Help Restore the Peace 

If you’ve found yourself constantly asking, “why is my gas furnace so loud?” it’s time to contact a professional for an inspection and diagnosis. At Hearn Plumbing Heating & Air, we’ve got you covered. Our team is prepared to handle any noise your furnace may be making. Give us a call today to schedule an appointment!