A noisy furnace will mess with the relaxing environment in your home. This, in addition to the fact that furnace noises are usually an early symptom of serious problems, makes detecting and fixing the sources of these noises a must. The following are the most common causes of furnace noises that you should know.
Expanding and contracting ductwork
When you start your furnace, it starts pushing warm air through the ducts. This causes the ducts to expand. And when the furnace stops running, the air inside these ducts cools down, something that then causes the ducts to contract. Since most ducts are made of metal, this expansion and contraction will produce popping sounds. Popping sounds can also be produced when the air being pushed through the ducts blows past a loose metallic flap in the ductwork.
You can get rid of these popping noises by reinforcing the walls of the ducts so that they are less susceptible to shrinking and expanding. Making the change from metallic ductwork to fiberglass-lined or fiberboard ducts will also work.
Furnaces have a lot of moving parts such as motors. As a result, different parts of the furnace usually vibrate when the furnace is in operation. If the screws holding your covers and other devices get loose, they will cause exaggerated vibrations that will produce irritating noises. Solving this problem involves tightening loose screws and replacing any worn-out or lost fasteners.
A slipping belt
In order to transfer the power of the motor to the fan, the furnace takes advantage of a belt. With time, this belt wears out. It can also stretch, making it loose. Both of these things will cause the belt to slip. And since it is not running on its path, its rotation will be inefficient. It will lead to a lot of friction that will accelerate the rate at which the belt wears out. It will also cause squealing noises.
If you hear squealing noises coming from your furnace, your belt is to blame. Get rid of this noise by removing the access panel and then changing the distance between the motor and the fan pulley so as to create better tension. If this doesn't work, simply replace the belt.
Shot motor bearings
Bearings help the motor to work efficiently by reducing the amount of friction generated when it rotates. When these bearings wear out, the motor's rotation becomes labored due to the increased friction. This increase in friction will not only damage your motor, but also produce grinding noises. Replacing the worn-out bearings will fix this noise problem
If you can't figure out what is going on with your furnace or are uncomfortable making any of the fixes listed, reach out to someone that specializes in heating repair.