Furnace Noises: What’s Abnormal?

furnace repairman installing a heating and cooling thermostat

We know the regular sounds our furnace makes when it kicks on, but what about when you hear unfamiliar furnace noises? When it’s wintertime in the greater Aurora area, homeowners want fully functioning and efficient heaters in their homes. But in order to make sure this is the case, it’s vital that you properly care for said system. Given how much use your furnace will get this season, it’s important to keep in mind the issues that can crop up.

Maybe last year you heard a faint rattling or humming noise that didn’t seem to bother you, but it got louder this year and you’re wondering if you should call in a pro. To be on the safe side, we’re going to go ahead and say, yes! You should.

Now, no furnace is completely silent. There are some sounds you can expect—like the flexing of your ductwork as it adjusts with the temperature fluctuations, or the rumble of the motor—even the whoosh of air coming through your vents. But if you hear any of the following noises, you should know that they are abnormal:


Does the sound coming from your furnace resemble a tea kettle? This is one of the more unusual noises you may hear from the system. If you are hearing this, you may think that something is punctured, or out of place. What’s probably going on is that you have a clogged up air filter, restricting airflow.

The good news about this problem is that you can easily resolve it! Changing your air filter is the one maintenance task that homeowners can and should do on their own—every 1-3 months depending on the type of filters and the level of contaminants in their homes.


Now, this might be something benign. For instance, rattling can indicate a loose panel on the cabinet that just needs to be screwed in tighter. But, it could also be a loose component within the furnace that is banging around and potentially causing a negative domino effect inside your heater.

If you hear this noise coming from your furnace, the best thing you can do is have a professional come out to inspect and pinpoint the exact cause of the sound.


That brings us to booming—are you hearing what you would describe as a banging, thudding, or booming when you start up your system? This is typically a sign that your burners have become so overcome with dirt and grime over the years that gas has to burn through the grime before the burners can ignite.

This is not only detrimental to your heating system, but it could be unsafe for your household as well. Please be sure to schedule a maintenance appointment if you haven’t done so within the last year—cleaning the burners is an important part of gas furnace maintenance!


You may wonder what the difference is between rumbling and rattling—we describe rattling as a tinny or hollow sound—a noise indicating something is loose. Whereas rumbling is a low, grumbling noise that can indicate a problem with the burners.

No matter what’s going on, if you suspect something is amiss with your heating system, the best thing you can do for your household safety is to contact our pros.

Contact Aurora Plumbing Company today for furnace repair in Parker, CO. We have someone in your neighborhood today.


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