Why Does My Furnace Make a loud Squealing Noise?
Squealing noises in furnaces are fairly common.
The furnace blower motor (fan motor) is making a squealing noise?
Furnaces can generate a large number of noises. Those noises are usually described as:
Most of these noises are nothing to worry about and nearly all of them can be solved with a minor maintenance visit.
Squealing noises are caused by a rotating motor. If your furnace is old enough to have a belt that squeals you should have replaced in the last century. Furnaces that old can become very dangerous very quickly.
The Squealing Noises Can Come From a Couple of Areas:
The induced draft motor has worn bearings.
How Large is the Flexible Gas Connector Attached to Your Furnace?
On the label to the gas flexible connector it will state how many Btu's of gas it is rated for. A flexible gas connector is is radically too small can emit a squealing noise as the gas is traveling through it.