Furnace Blower Noise - What To Do With A Noisy Furnace Blower 

There are a variety of reasons why you may have a furnace blower noise. As with many other problems, unless you are able to make the correct diagnosis, you won’t be able to fix the problem. In this article we are first going to look at the gas furnace and secondly look at some possible causes for furnace blower noise by discussing the type of noise you may hear.

The domestic gas furnace is made up of primarily three parts. The first part comprises the burners and heat exchangers, draft inducers and venting. The second part is made up of the parts which ensure that the furnace operates safely and the third part is made up of the blower and air movement. We will look at this part of the furnace to determine the source and possible solution to furnace blower noises.

If your furnace blower is making a grinding noise, it is very likely that the motor bearings are damaged. This is a problem for the repairman. These bearings will have to be replaced. Worn bearings may also result in a moaning noise. Check to see if there is any play in the motor shaft. If you hear a furnace blower noise that sounds like a grinding, rattling or whining when the furnace is turned on and the fan picks up speed, then it is likely that the bearings in the fan blade or motor are going. This needs expert help.

Your furnace may make a squealing noise. In this instance, it may be that the belt that connects the fan to the motor has slipped. It is likely that the belt is improperly aligned or has become worn and needs to be replaced. If this is the problem, you may also detect a smell of burning rubber. Use the owner’s manual to guide you in its replacement. To correct this, remove the access panel to the blower, loosen the bolts holding the blower motor and remove the old belt. Make the replacement and be sure to not over tighten as this will cause the motor bearings to wear out.

There may also be instances in which the furnace blower noise is being caused by motor bearings which need to be oiled. Poorly lubricated motor bearings may cause a squeaky noise to be heard from the furnace blower.

To fix a furnace blower noise, also look for loose parts and screws which may be contributing to the noise. Be sure to tighten them if you find them during your examination. You may also check that there is nothing lodged against the blower wheel which may be causing noise.

There are some instances in which the furnace blower noise is a result of the type of furnace rather than a fault in the operation of the furnace. If you have done your troubleshooting and the blower noise still remains, you may consider soundproofing. This might be more appropriate for Recreational Vehicles furnaces than others.

To correct your furnace blower noise, you may need to engage the help of a trained HVAC professional. You may attempt to identify the problem using our suggestions above. If you are unable to reduce or stop the furnace blower noise you may have to get professional help.