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3 Furnace Noises You Shouldn’t Neglect

Changing furnace filterDuring the winter months, you rely on your heater to keep your home warm and comfortable regardless of how low the temperatures dip outside. For the most part, modern furnaces used for residential heating function flawlessly in fulfilling that role, as they can run for years without any significant issues so long as regular maintenance is performed. However, like any mechanical system, they will eventually break down and experience degraded performance. That can cost you money and provide you with heating that leaves something to be desired.

For some homeowners, the first sign that their furnaces are experiencing problems comes through a litany of strange noises emanating from the furnace itself. While most furnaces operate quietly when functioning properly, the development of unusual sounds can be an indicator that something has gone awry in the furnace closet. While some noises may not be cause for concern, there are a few that warrant immediate attention from heating services in Buckhead. Keep reading to learn more about what noises you simply can’t ignore when it comes to your furnace.

Scraping or Grinding

When your furnace comes on, you expect to hear a low hum and maybe the sound of rushing air as your blower motor kicks in. However, if you hear the harsh sound of metal-on-metal scraping or grinding, you have reason to be alarmed. When that sound is present, it means that there is an immediate need to turn the furnace off, since metal scraping against metal shouldn’t happen during normal operation of your furnace. The sound can be traced to several of the moving parts in the furnace and heating system, but the most likely source of the sound is usually the blower wheel, a component that helps move the heated air throughout your house. If it’s in any way impinged, that can cause the sound. If the blower wheel isn’t functioning properly, your furnace will waste energy and your home can’t be heated. Therefore, you should contact a professional service technician immediately.

Popping or Banging

Likewise, if you hear a loud popping or banging sound when you turn on the furnace, there’s likely a problem that needs to be addressed immediately in the interest of furnace performance, energy efficiency, and safety. Unlike some of the other sounds that can come from your furnace, popping or banging can come from a variety of causes. The most common cause of such a sound is dirty furnace burners. The burners in your furnace feature tiny holes that can collect carbon from the burned gas over time. When the burners get dirty and become clogged, it can delay ignition of the gas that flows into the component when the furnace is turned on. Delayed ignition allows more gas to build up, and when it does ignite, it can create a tiny explosion that generates the noise. Those explosions can lead to bigger problems, such as cracks in the heat exchanger, and should be remedied immediately.


ThermostatSquealing is another furnace noise that demands immediate attention because it could be a sign of a failing part that can cause greater damage to your heating system when it fails completely. While squealing could signify something as simple to fix and mundane as a bad belt, it can also be a sign that a moving part such as a bearing, pulley, or blower motor is about to fail. When that happens, additional damage could be done to the furnace if it’s allowed to continue running. When you hear squealing, contact an HVAC technician to help you diagnose the source of the sound and correct it before additional, more significant damage is inflicted upon your system.

If you hear any of these 3 sounds coming from your furnace, turn it off immediately and contact an HVAC professional to help you track down the cause and make the proper repair. Call Cool Air Mechanical at (770) 266-5247.

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