Is Your Furnace Making Odd Noises?

If your furnace (heater) begins making loud or strange noises, it might be a warning sign of trouble. Furnaces are usually the one appliance in your home that can be neglected. However, you probably recognize what sounds should be coming from your furnace when it’s performing like it’s supposed to, so anything out of the ordinary needs your attention. Your furnace could get your attention by making several of these sounds.

  • Screeching Noise: If you hear a screeching noise, it might be something wrong with the motor, or a bearing inside the motor that is producing the noise.
  • Metallic Chirping Noise: If you hear a metallic chirping noise, it might be caused by the wheel moving out of alignment, a motor mount might be broken or loose, or your bearings could be going out. On occasion you might be able to wriggle the wheel to get the alignment to resolve itself, but if you don’t know what you’re doing, it’s always a better idea to have an accomplished HVAC tech handle things.
  • Rattling sound: If you hear a noisy rattling sound when your furnace shuts off, it is usually the metal parts to your furnace cooling down. However, it may also be something more serious. The blower could be out of alignment or an error in the motor occurred. If you hear this noise you should give our team a call.
  • Clanging noise: If you hear a clanging noise, the problem is most often in the pipes, instead of the furnace itself. This tends to happen when the pipes are able to cool down and contract after the furnace turns off.
  • Loud Boom or Thud: A loud boom or thud sound may have come from the ducts. They can expand and contract in cold weather, especially if the furnace’s surroundings aren’t heated. However, it might also be an indication that the burners in the furnace are dirty and could stand to be cleaned. These are relatively easy to clean on your own if you use hot soapy water. If you want to clean these yourself, be sure they are fully dry before reinstalling them. If you learn that it’s not the ducts or the burners, it might be that your gas valve is malfunctioning (assuming you have a gas furnace), which can cause a delayed ignition. In many cases, it is wise to call so one of our expert HVAC technicians can troubleshoot the problem.
  • Pinging and or Popping: A pinging or popping sound is most likely coming from one of the ducts and is not generally something to fret over.
  • Odd Vibrating Noise or Whining: If you hear an odd vibrating noise or whining, it may indicate a problem with your furnace. It could be serious, so a heating technician really needs to check it out.
  • Loud Humming: A loud humming noise may come from when the furnace burners light and it's cold outside. You can prevent this noise by turning the “off/pilot/on” control to reduce the burner flame.
  • Rattling Noise When the Furnace Starts Up: If you hear a rattling noise when the furnace activates, it might be a motor bearing going out.
  • Crackling Noise: A crackling noise is more than likely a result of the metal parts of your furnace cooling down when the furnace shuts off.
  • Clunking and Banging: A clunking and banging sound is often a cracked belt. If you hear this noise you need to have a furnace repair┬átech visit your home to replace the belt.


If you want to be on the safe side, if your furnace is making sounds that are are unusual its certainly a good idea to schedule one of our NATE Certified HVAC technicians to come out to your home to do a system diagnosis to uncover any potential problems before it’s too late. As they say, an ounce of prevention is worth a pound of cure.

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