The furnace in your home will often make noise, especially older models. Normal sounds are minor pops from the ducts and the humming of the furnace as the blower runs. But if the noises you are hearing are loud enough to keep you up at night, make sure to contact us so we can inspect the furnace system for you.

Ignoring these noises would be a big mistake since what is causing them could lead to even more costly repairs later on. Here are some noises that you should never ignore for your furnace.

Loud Scraping

A loud scraping noise that sounds like metal rubbing metal or nails scratching a chalkboard probably means something is wrong with the furnace’s blower wheel. Several things could cause this issue. The blower wheel came loose from the motor shaft and is now hitting the blower casing. The blower wheel could also be broken and needs to be replaced. Also, the motor mount could be broke, which could cause the whole blower assembly to drop and hit the housing.

Loud Bang or Pop When the Furnace Turns On

The dirt on the furnace burners delay the burners from igniting, causing an excess of gas to build up. So when the gas does finally ignite, you will hear a loud bang. You should never ignore this noise because these small explosions could crack the heat exchanger.

Expanding and contracting air ducts is a common noise for homeowners that have metal ductwork. The ducts expand and contract as the blower turns off and on. This could be a sign of undersized ducts, closed vents, flimsy ducts, or a clogged air filter.

Squealing or Whining

A high-pitched squealing noise is caused by:

  • Loose, slipping, or fraying blower belt,
  • Shaft bearings that need oil, or
  • Malfunctioning blower motor

This squealing or whining noise is not as big of a deal as the others listed above, but it is best to get it fixed before it causes any further troubles inside your furnace. No matter what noise you hear, if it happens on a regular basis, make sure to contact us so we can inspect the furnace for you.