Why does my heater keep making noise?

Author: Davon Luettgen V  |  Last update: Friday, July 18, 2025

Problems with the ignition components, such as dirty ignitors or a dirty burner, can cause a buildup of gas inside the combustion compartment, and when the heating system ignites, it can signal a larger-than-normal explosion inside your furnace that creates the sound.

How do I stop my heater from making noise?

Turn off power to your heating system. Open the panel to the blower compartment so you can see the fan belt and motor. Check for signs of fraying and wear – a damaged fan belt needs to be replaced. If the belt is loose, it needs to be tightened – there shouldn't be more than a half inch of give in either direction.

Why is my heater making a weird noise?

There could be a few reasons why heaters make this sound, like dirty burners that need cleaning, or an excessive amount of gas inside the chambers. If you hear a banging or popping sound when the heater shuts off, it could mean your ductwork is contracting as the metal cools down.

When should I worry about my furnace noise?

Loud Bangs, Rumbles, Knocks, or Booms

Loud noises like this are a sign of a build of gas in a furnace. The noise you hear can mean your heat exchanger is at risk of cracking. Even worse, it's a sign that something dangerous could happen if you continue to use your heater.

Why is my heating making a loud noise?

Most frequently, the cause of a noisy radiator is air being trapped inside the system. If this is the case, it is recommended to fix this issue as soon as you can. If you find you can hear noisy pipes (especially during colder weather) this could be down to a frozen condensate pipe.

Noisy Furnace? - Top 5 Fixes | Repair and Replace

How do you fix a loud heater?

In fact, a clogged air filter is one of the few causes behind a noisy furnace that you can fix yourself. Just change the filter, and the noise will stop.

How to stop heating pipes from making noise?

In most cases, noisy pipes are caused by movement as they expand and then knock against other surfaces. Therefore, one of the best ways to solve this problem is to check that all pipes are securely fastened and that they're not touching anything else.

Why is my furnace suddenly so loud?

If the sound is louder than typical and lasts longer than normal, it can be a sign of a problem with dirty burners, high gas pressure, or a malfunctioning heat exchanger, all of which could compromise the equipment's functionality and safety.

Why does my furnace sound like a plane taking off?

If your furnace is making an obnoxious noise, it's likely because the furnace blower motor is turning on and off as part of normal heating furnace cycles. Make sure your thermostat is set properly to the desired temperature and off when you don't need heat (like overnight).

What does a failing furnace sound like?

Thumps and bumping noises, like an unbalanced washing machine, often indicate an unbalanced blower wheel or motor. This is a serious issue that requires immediate HVAC repair. The blower wheel and motor are major furnace parts and you don't want them bouncing around.

Why can I hear my heater?

There are a variety of problems that can cause your furnace to produce loud noises. Types of noises such as scraping, banging, whistling, and popping may be a sign of a loose part, cracked heat exchanger, or dirty gas burners.

How much does it cost to replace a furnace?

First, know if you have a gas, electric or oil furnace. Electric furnace installation tends to be the least expensive, ranging between $3,000 and $7,000, according to HomeAdvisor. Installing a natural gas furnace falls in the range of $3,800 to $10,000, and an oil furnace ranges $6,750 to $10,0000.

What does a cracked heat exchanger sound like?

Instead, you should take immediate action and contact an HVAC professional. A cracked heat exchanger can produce different sounds, including popping, banging, whistling, or scraping.

Is it okay if my heater makes noise?

Though rattling, whistling and humming are usually not causes for concern, you should not ignore some noises. Switch the furnace off and call SMO Energy if you hear any of the following from your heating system: A bang. A boom.

How long do furnaces last?

The Average Furnace Lifespan

A well-maintained furnace can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend its life even longer.

Why does my furnace make noise when not running?

Air Drafts Causing Rattling

Air flowing through ducts and vents can lead to rattling or whistling noises as the furnace cools down after being switched off. Check for cracks or disconnected ductwork that could allow drafts to enter. Insulating your ducts can help muffle these sounds.

Why is my furnace making a continuous sound?

A constant low buzzing or humming noise could indicate an electrical problem. This could be anything from a faulty capacitor, a problem with the fan motor, or an issue with the transformer.

What does it sound like when a furnace is going out?

We're here for the long run. So if you hear a squeal, a new click, grinding, or popping when your furnace is at any point in the heating cycle, it's best to have a tech take a look and catch things early.

How do I stop my furnace duct from making noise?

Insulate Your Ductwork

If your ductwork isn't properly insulated or doesn't have insulation, add insulation to duct runs in the basement or attic. The insulation should be formed and designed to insulate ducts. The insulating material will muffle loud noises from within and it can improve energy efficiency as well.

Why does my furnace sound like a lawn mower?

If your furnace produces a loud humming or buzzing sound, there could be an issue with the motor. There may also be something wrong with the fan. It can be something as simple as a loose screw, loose door, or improperly installed furnace filter.

How do I quiet a noisy furnace?

How to Quiet a Noisy Furnace Blower
  1. Check and Replace Any Loose Parts. ...
  2. Fasten the Furnace Motors. ...
  3. Oil Furnace Motors. ...
  4. Check Your Blower Fan. ...
  5. Adjust the Speed of Your Furnace Fan. ...
  6. Clean the Air Ducts. ...
  7. Fix Damaged Insulation.

Should you be able to hear your furnace?

On a normal day, your home's furnace might make a little noise as it starts up, when it's turning on, and then when it turns off. You can always expect to hear some noise from the furnace. The thing about this noise is that it should never be disruptive.

Why does my heating make a noise when it comes on?

Other causes of noise in the central heating pipes can be attributed to air in the system. Light tapping noises, clicking noises, or even a gurgling type sound can be caused by radiators that require bleeding. This is easily solved by opening the bleed valve to allow excess air to escape.

How often do you need to bleed radiators?

You should bleed your radiators at least once a year, typically before winter arrives in order to ensure the efficiency of your heating system. Regularly checking for trapped air also helps to make sure that your system operates effectively and reduces energy consumption.

How to get rid of air in a heating system?

Step 1: Turn off your central heating and wait for around 20 minutes for the system to cool down. Step 2: Lay a dry cloth or towel beneath the radiator you want to bleed, just in case any water escapes. Step 3: Use your radiator key to slowly open the valve, turning it anti-clockwise to do so.

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