Here’s how to troubleshoot strange furnace sounds or noisy furnace ducts

over 1,500 reviews

All HVAC systems, to a degree, make noise while operating. However, how do you know if these noises are normal or an indicator that something is wrong? If you’re hearing strange furnace sounds or experiencing noisy furnace ducts, it could be either business as usual or a sign of trouble.

In this article, we’ll review the wide variety of sounds that your furnace and air ducts can make, and which ones should lead to you giving us a call for furnace repair here in Buffalo and Western New York.

Hearing strange furnace noises?

It might not be just your imagination. Out-of-place furnace or ductwork sounds could be your warning that something is wrong with your heater.

Click the link below to learn more about our Day or Night furnace repair services.

Start by ruling out potential furnace problems

Before you start thinking about what sounds are coming from your ducts, you’ll want to rule out that the sounds are coming from your furnace. There are several different furnace sounds that signal potential trouble. Here’s why you need to keep an ear out for popping, screeching, and rattling.

Popping Sounds

The sound of a loud “pop” coming from the furnace could be a sign that the furnace is igniting too much gas in the combustion chamber. In most cases, the root cause of this issue is a defective gas valve or dirty burners. Basically, what you’re hearing is a (small) explosion inside of the furnace.

This is something that you’ll want to get checked out by a gas furnace professional. Eventually, the furnace flame sensor—a safety mechanism that checks for the presence of a flame to ignite the gas—may kick in, shutting down your furnace.

If you have an electric furnace, you’re not likely to hear this problem.

Screeching Sounds

A loud screeching sound is not a natural part of a furnace’s cycle. It’s probably an issue with the blower fan’s belt. As these belts age and wear, they begin to fray and cause strange sounds.

If you’re hearing a distinctive screech coming from your furnace, it’s probably not something you want to ignore for too long. Call our team and have us out to inspect the system. Left untreated, these could lead to your furnace breaking down for good.

Rattling Sounds

Chances are that you do not have a rattlesnake in your furnace, so the likely culprit of a rattle is something that is loose. The furnace produces a harmless low-frequency hum while in operation. Anything that’s loose—from screws and components to the heat exchanger itself—could start rattling from this natural vibration.

Again, this is something you’ll want one of our technicians to help you diagnose. The rattling of a loose part is typically an early warning for an impending breakdown.

Diagnosing the sounds made by noisy furnace ducts

Now that you’ve eliminated the possibility that the noise could be generated by your furnace, it’s time to turn your attention to your ducts. Here are some of the most common sounds made by noisy furnace ducts while your heater is running.

Banging Sounds

Once you’ve ruled out the sound coming from the furnace itself, the next likely explanation of a loud popping or banging sound is the ducts.

As hot air enters a cold duct, the metal expands and warps in response to the sudden temperature change. This leads to the metal “banging” as it shifts into place. This same phenomenon occurs when a duct, once filled with hot air, cools down after the furnace has been shut off.

This sound is pretty harmless, and it’s natural to hear it whenever your furnace turns on or off.

Rattling Sounds

The rattling noise is most often caused by loose metal ducts that tend to knock against one another. This could be a sign that your ducts have leaks or gaps between them, which will ultimately have a negative impact on the performance and efficiency of your heating system.

As ducts age, the connective sealing between them begins to deteriorate or loosen. This isn’t going to cause a breakdown or anything, but it’s still worth having a Reimer technician look into this winter.

Vibrating Sounds

A sound of vibrating or shacking of the duct walls normally occurs due to the blockage of the return side airflow. This usually happens due to a clogged filter that results in a drop in the air pressure that makes the duct walls vibrate and shake.

Booming Sounds

A loud booming noise coming from the ducts typically emanates from the plenum where all the ducts meet. This connecting point tends to endure the greatest swings in temperature.

Inadequate expansion of joints or dampers contributes to the noise. What you’re hearing is a loud boom echoing through the supply ducts.

Whistling Sounds

In some cases, you can hear a whistling or rumbling noise emanating from the ductwork. The whistling noise is normally caused due to excessive airflow through the ducts.

On the other hand, the rumbling noise could be due to pressure differences between the supply and the return ducts.

What are the other signs you might need furnace repair?

Strange noises are only one of the signs that your furnace might need repairs. Performance, efficiency, and comfort issues can also signal that something is wrong.

Read our blog post to learn more.

Call Reimer to have our team diagnose noisy furnace ducts

When it comes time to care for your furnace or your ducts, make sure that you hire an experienced and licensed furnace technician.

An experienced technician will expertly identify and resolve all kinds of furnace problems due to which you can spend the entire winter months in total comfort and warmth.

At Reimer Home Services, our experienced techs are ready to assist you with diagnosing strange furnace noises and the source of noisy furnace ducts. Contact us today to schedule service here in Buffalo and Western New York.

What Our Clients Say

Chris and Kevin were excellent! The issue involved plumbing. Accomplished all that was needed at the time. They are returning for additional work as well. The annual contract has great value , and gives homeowner piece of mind when problems arise! I just signed up for mine!

-Kitty Testa

Chris L. Is a wonderful man. Put my mind at ease immediately when he looked at the problems which turned out not to be as bad as we thought. I will definitely use them again. Great service!

-Janice Kaled

Chris Reimer was at my home and did a great job was very nice guy to have work in my home and gave me no run arounds. I would for sure use again thank you very much!!

-Matthew Dillon

FROM THE BLOG
Want to learn more about heating and cooling?
We’ve got you covered.
5 SIGNS YOU NEED TO CALL A PLUMBER: DRAIN BLOCK ADDITION Out of sight, out of mind. You may have heard this adage before, and when it comes to drains, this saying certainly rings true. Our...
AVOID THESE COMMON GARBAGE DISPOSAL PROBLEMS DURING THE HOLIDAYS The holiday season is a time for celebration and gathering with loved ones. With all the cooking and food preparation that takes place, it is...
DRAIN CLEANING SERVICES – WHEN ARE YOU IN OVER YOUR HEAD? When To Call A Plumber For Drain Cleaning  As a homeowner or property manager, you need to always pay attention to the day-to-day inner workings...

Authorized Dealers