Why is my heater making a weird sound?

Author: Margarete Hermann  |  Last update: Sunday, June 22, 2025

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.

Why is my heater making a weird noise?

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.

What do you do when you hear strange noises coming from your heating system?

Heating system makes strange noise due to air bubbles trapped in the water of your central heating system. You can use a radiator bleed key to release the air from the system to overcome the noise issue.

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 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.

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.

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 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).

Why is my house making loud banging noises?

If you hear similar clanging or loud banging noise in the walls, it can be a sign of clogs or air pressure in the system called a water hammer. If you don't resolve the problem, it can cause damage to the pipes, so consult a professional.

Why is my furnace so loud all of a sudden?

If your furnace suddenly produces loud, sudden banging or booms, you should call an experienced technician as soon as possible. These sounds could indicate stuck ignition, a potentially dangerous situation involving carbon monoxide which is deadly.

Should I be able to hear my heating?

It's often said that you shouldn't be able to hear a central heating system that's running well and efficiently. Your heating should come on and off seamlessly with little to no noise.

How do I stop my heating ducts 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.

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.

Why does my furnace make a noise at night?

MY FURNACE IS MAKING A THUMPING NOISE

Things that go thump in the night or any other time mean something is out of balance. Thumping sounds that come from your furnace could indicate that a motor or blower wheel is out of balance. This could cause big problems for your mechanical equipment down the road.

How often should I change my furnace filter?

For 1- to 2-inch filters, replace them every 1 to 3 months. For 3- to 4-inch filters, replace them every 6 to 9 months. For 5- to 6-inch filters, replace them every 9 to 12 months.

Why does my heater sound like a jet?

Blocked or closed vents can cause increased sound pressure as the furnace blower motor and fan push air through, resulting in a “jet engine” sound.

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.

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.

Why is my heater making noise when it's off?

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.

How do you know if your furnace died?

The pilot light in a well-functioning furnace should be blue and vibrant. Pale or weak flames indicate a problem with the amount of gas burning. If your pilot light is wavy or flickering, the gas may not be thoroughly burning. This could indicate a leak, inefficiency, or another issue.

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?

When your heater turns on, noises like popping and banging are normal. 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.

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.

How much is a new blower motor for a furnace?

While costs can vary, homeowners can typically expect the following range: Standard Blower Motors: These might cost between $400-700, excluding labor. Advanced Multi-Speed or Variable-Speed Motors: These are generally more expensive, with costs ranging between $650-1250, not including labor.

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