Why Is My Furnace So Loud?

loud noises, furnace noises, heater repair, heater maintenance, furnace tune-up, furnace replacement

A well-maintained heater helps manage your indoor air quality, keeps your home toasty and — for the most part — stays silent. Like most mechanical devices, a furnace will generate a small amount of noise. Namely, you should expect a gentle hum when first activating your system.

However, if a particularly loud noise has drawn you to this article, it’s probably a damaged heater’s cry for help. Reach out to Boone’s Heating and Air Conditioning to get your system repaired and restore the quiet in your home.

Until then, you can review these common furnace noises, their causes and potential fixes:


As previously mentioned, a low hum shouldn’t raise any red flags, especially if you haven’t used your heater in months.

That being said, an especially irritating and persistent hum isn’t normal. A failed capacitor or poorly lubricated blower motor are typically to blame. In both cases, you’ll need a professional technician to either repair or replace these faulty parts.


Piercing squeals are among the most alarming furnace noises. Something has probably hurt the fan within your heater, leading to unbearable screeching. A worn-down fan belt is the most common culprit, which a professional will need to replace.


Some homeowners experience a thunderous rumbling from their heater, much like the sounds from a noisy laundry machine. This loud noise merits more immediate attention, as it’s typically the result of abnormal burning in the system’s combustion chamber.

Reach out to an HVAC technician right away to get your burners, flame sensors and pilot light examined.


A damaged furnace fan can make your home sound like a helicopter landing pad. A professional can best identify the exact mechanical issue producing uncontrollable whirring. More often than not, a minor repair will take care of it.


Like humming, this sound is completely normal under the right circumstances. When your heater is turning on or off, you should expect some quiet clicking. However, if the noise persists the entire time your system is activated, you’re dealing with an ignition issue.

A damaged valve may be interfering with your ignitor, leading to repeated clicks similar to those of a jammed lighter.


When your heater is working properly, it helps dehumidify the air, drawing in excess moisture and sending it away through a drain pipe. A clogged pipe disrupts this process, leading to noisily bubbling water.

You can attempt to resolve this issue yourself by pouring a half-bleach, half-water solution down your system’s drain pipe. However, if you aren’t comfortable navigating your furnace’s internal parts, the unclogging is best left to a professional.


Although a loud bang might make you jump, there’s no reason to panic. In most cases, banging comes from air ducts expanding or contracting as your home’s temperature changes.

Less frequently, banging might signal a cracked heat exchanger. If left unaddressed, this can lead to carbon monoxide leaks. Wait for a little to see if the banging subsides. If it doesn’t, find professional help as soon as possible.

Find Heating Repair in Farmers Branch

Many of these furnace noises, if persistent, demand attention from experienced HVAC technicians. Boone’s Heating and Air Conditioning has conducted dozens of Farmers Branch heating repairs, meaning our team is well-trained to address your furnace troubles.

Request a service appointment today to eliminate disruptive heater sounds. In the future, consider scheduling a heater tune-up to ensure your home (and eardrums) are protected from long-term damage!

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