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.
It's normal if it's the gas jets. Go down to your furnace and open the access panel, then turn the heat up and see if the sound comes from the jets.
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.
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.
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.
Furnace Screeching or Scraping
The blower fan may have come loose, letting the blades drag across the furnace casing. A scraping noise can also indicate other parts of the system have loosened. If you are unsure of the cause of the noise, turn the furnace off and have a technician come and take a look at it.
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.
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.
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).
If you're hearing a loud banging or booming noise, this could indicate your furnace has dirty burners. This is hazardous as it can hinder the ignition. This delay in ignition triggers a gas build-up, producing a little explosion when it finally does light. Your burners should be regularly cleaned to avoid this issue.
Many furnaces produce a dull humming sound while running. However, if your furnace produces a loud humming or buzzing sound, there could be an issue with the motor. It could also indicate there's something wrong with the fan.
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.
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.
If you've lived with a gas furnace at any time in your life—and most people have—you'll know what sounds to expect from it: the whoosh of the burners igniting, the clicking of the ignition as it comes on, the whir of the blower fan, the movement of air through the vents, and an occasional rattle as the metal vents ...
The Motor or Belt Is Damaged
Gas heaters rely on powerful fans to draw in air and distribute heat throughout your home. If the belt or motor connected to this fan loosens or is damaged, your unit may emit a screeching or whining noise.
Loud Grinding (Metal Rubbing Metal) Noise
If you hear this noise, turn off your furnace immediately to prevent any further damage to the system and call a professional to perform a furnace repair project. A few blower wheel problems include: Blower wheel is loose from the motor wheel.
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.
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.
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.
Your Heater Makes Loud Noises When Shut Off. The noise your heater makes when it turns off is caused by the expansion and contraction of the metal parts in the device. They make a clicking, squeaking sound as they move. It's important to note that not every household has this problem.
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.
Tighten the motor mounts and see if that solves your issue. If it doesn't, insulating the blower might be the best solution. If that doesn't work, then you may need to replace the whole blower. If the annoying sound is a screech, you might just need to oil the blower motor.
Banging, popping and rattling noises often indicate there is a problem with the blower assembly, motor, or furnace burners. Repeated clicking noises often indicate that there is a problem with your furnace's ignition system.
However, most gas furnaces typically last between 15 to 20 years before efficiency declines and repair costs increase, so it's wise to consider replacement around the 15-year mark to ensure optimal performance and safety.