Furnaces have a lot of advantages as a heating appliance. They're efficient, relatively affordable, and fairly easy for HVAC contractors to fix. One downside of furnaces, however, is the noise they make. A furnace that is working well won't make much noise, but when something is wrong, furnaces can get downright loud. This can be a good thing in some ways; it makes it easy to tell that something is amiss. Most furnace sounds boil down to one of the three S's: Scraping, squealing, and slapping. Here's a look at each of the three S's and what each one is likely to mean.
Does your furnace make a sound that sounds like metal scraping against metal? The scraping might be slow when the furnace first starts up, speed up while the furnace is operating, and then slow down again as the furnace is turning off. Usually, this scraping sound means a ball bearing in the fan motor has become worn and flat. Instead of allowing parts to slide past one another, the ball bearing is creating more friction and scrapes against one of the moving parts.
Luckily, furnace repair contractors can replace a ball bearing without too much effort. They'll undo a few screws, pop the old bearing out, and put a new one in. It's important to have this work done before the worn ball bearing scrapes away too much material from another part it is resting against.
If your furnace is squealing and squeaking, this is usually because the belt in the fan motor is damaged. It may be fraying, and the squealing could be the increasingly thin belt rubbing on the mechanisms it connects. Replacing a fan belt is a little more extensive than replacing a ball bearing, but it's still a rather routine repair for an HVAC contractor to make.
Slapping could also be called thumping. It sounds like something is repeatedly hitting the side of your furnace as it operates. Usually, this happens if the blower motor is out of balance. This can occur if your foundation shifts and puts the furnace out of balance, or if someone bumps into the furnace with something heavy. Have an HVAC contractor come to put the furnace back into balance before the situation causes more extensive damage to the motor.
Now you know what each of the three S's means and should be better equipped to seek care for your furnace. Good luck, and stay warm.
Contact furnace repair services to learn more.