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Bartels Heating & Cooling Blog

Diagnosing Noises from Your Heater

woman-ears-covering-handsThe hum of your heating system as it starts its cycle as usual is, of course, nothing to be alarmed about. You know the normal noises your heating system makes, which means you know when something is off. Typically, a sound from your heating system may not mean that your system is in any immediate danger, but it often still means you should call in technicians ASAP.

Want to know what those noises really mean? Check out our guide to some common sounds below, but be sure to reach out to your local technicians for boiler or furnace repair the moment you notice a problem!

Banging or Popping

This is easily one of the most alarming noises you can hear from a furnace. Which means you should call in a technician ASAP! Even if you’re not in any immediate danger, it could be soon to follow.

Dirty burners make it more difficult for the burners to light, which means that a lot of gas may be built up by the time they finally do. That loud banging noise indicates the burners have finally lit, but that a type of explosion has happened at the burner. This can slowly damage the furnace, including the heat exchanger—which could leak carbon monoxide (a toxic gas) into the home.

In a boiler, this noise can indicate something quite different. While it may have to do with the burners, a loud popping or banging is usually the result of scaling.

Hard water can cause minerals to buildup in such a way that they coat the bottom of the hot water tank. As steam bubbles attempt to escape to the top of the tank, the minerals rattle around, throwing off the pressure of the tank and wearing down the bottom, leading to faster corrosion rates.


That scraping noise, or a screech, from the direction of your furnace or the vents likely has to do with the blower fan. You may have even heard this noise begin during the air conditioning season. There could be a few fan issues causing it to sound like metal scraping metal:

  • A loose blower wheel that needs adjustment.
  • A broken blower wheel that needs replacement.
  • A broken blower wheel mount that is causing the fan to hit the casing.


A squealing sound from the fan and the furnace often indicates a lack of maintenance on the part of the furnace owner. In fact, many of these issues could be prevented or better managed with the help of a professional preseason or early-season maintenance session.

Once again, the blower fan is likely at fault. As one of the only moving parts, it’s often responsible for a furnace noise. The blower wheel has a belt that can wear down over time, and will need replacement every once in a while. This squealing noise can indicate a worn or fraying fan belt, a part that is easily replaced. Or, it could have to do with a squeaky blower wheel that needs a thorough cleaning.

For more information or to schedule furnace repair in West Chester, OH, contact Bartels Heating & Cooling today.

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