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Typically, when a heater makes a loud banging noise when it turns off, it’s the sound of metal contracting. As the furnace cycles, air is pushed through the duct system into your living areas. This backup of heat causes the metal of your ducts and the furnace itself to expand and bow outward.
When should I worry about my furnace noise?
Dirty Burners If you hear a sound like a loud bang or boom coming from your furnace, you would certainly be wise to be concerned. When the gas finally builds up enough the spark will finally ignite all that built up fuel and cause a small explosion inside your furnace.
Why does my heater make a loud noise when it turns on?
If you hear a loud bang from the furnace when it kicks on, it could be because of an issue with ignition. Additionally, the burners might be dirty or clogged, or the gas pressure might be low enough that ignition does not take place until there is a significant amount of it built up in the chamber.
Why does my furnace rattle when it turns off?
A noisy rattling sound when your furnace shuts off, it is probably the metal parts to your furnace cooling down. It might also indicate a problem with dirty burners in the furnace. You might be able to remove and clean these yourself with hot soapy water.
What does a bad furnace sound like?
Loud Pops & Bangs Homeowners often notice a popping sound when the furnace begins a cycle. This is due to warm air that hits the cold metal of the ducts, which causes expansion and produces that noise. When the popping noise is louder, your gas furnace’s burners may be dirty.
Why is my furnace so loud all of a sudden?
But if you hear a loud humming or buzzing sound coming from your furnace, it usually means your furnace has an electrical problem. The most common electrical issues that cause a humming or buzzing sound include: A failing blower motor capacitor. An aging or unlubricated blower motor.
How do I make my furnace blower quieter?
If you are wondering how to quiet a noisy furnace blower, you should try adding sound insulation to the system. You can install a melamine foam next to the blower intake. Try securing the foam using steel wire so that the furnace blower does not suck it in.
Can a furnace explode?
A furnace explosion is usually the result of ignition and instantaneous combustion of highly flammable gas, vapor, or dust that has accumulated in a boiler. The effect of the force from the explosion is often much greater than the boiler combustion chamber can withstand.
Why is furnace making a rattling sound?
A bang or rattling sound from your furnace could mean that you have a cracked heat exchanger, which is the biggest cause of carbon monoxide leaks. If you are hearing rattling while your furnace is on, however, it’s most likely because of loose connections in your duct system.
Why is my furnace making a knocking sound?
A knocking sound that occurs continuously while the furnace is running is a signal repairs are needed. The two most likely sources of the sound are bad bearings and a cracked or damaged belt. Dirty burners and a defective gas valve also can cause loud banging sounds.
What does a cracked heat exchanger sound like?
Audible Sounds. If you have a crack in the heat exchanger, you are likely to hear a rattling noise as your thermostat turns on the heat. Because the heat exchanger is made out of metal, as it is heated cracks will expand/contract, and can cause rattling, popping, and/or banging noises.
What does a bad blower motor sound like?
A defective blower motor will make a continuous sound noticeable by the passengers in the vehicle. It can manifest as a knocking, whirring, clunking, vibrating, squealing, or whining noise that persists until the blower motor is replaced.
Should my furnace be loud?
A majority of furnaces will produce a low humming noise while they are operating. If this noise is becoming noticeably loud, this is a signal of a severe problem with your blower fan or capacitor. To prevent damage to your fan, it’s important to call a licensed technician to inspect and repair the blower motor.
Why is my furnace blower motor so loud?
Most likely the blower fan has become loose and is creating the sound by hitting against the blower house casing. A metal-scraping sound needs to be addressed right away, and requires the attention of a professional HVAC technician.
How do I make my furnace stop making noise?
Your idea of adding fiberglass batt insulation to the floor joists over the furnace, along with a drywall ceiling, will help stop noise from penetrating the floor above. If doing this type of finishing work fits into your decorating plans, this would be a good way to accomplish two things at once.
Why is my air vent so loud?
Vents can make loud whooshing noises if the supply air ducts are too narrow. Debris can also block the ducts or cause one or more vents to close. You can use a flashlight to see if the vents look too dirty. However, you’ll need to reach out to an HVAC contractor if the noise persists.
How do you know if your furnace is going to explode?
These include high pitched, grinding, rumbling, popping, squealing, or banging noises. This could be the result on small issues like loose components within the system or more serious issues. Either way, you should call a professional to look into the issue.
