There are many ways to stop a humming noise on your furnace. One way is to turn the thermostat all the way up, which will prevent the furnace motor from starting unless it is already on. However, this method has its drawbacks, as it may cause your home’s temperature to be warmer than desired and will reduce efficiency by turning off parts of the fan and filter that you need. Here are tips to stop a furnace making humming noise:
Operate the blower
If the fan on your furnace is humming, you may need to lubricate it. However, if you notice a wobble or if the entire unit is shaking when you turn it on, then you need a new motor. If there is no shakiness and no wobbling, then check to see if the fan is loose by looking at the back of your unit. The fan may be moving or vibrating even when it has been shut off because of a loose screw or nut in the mounting bracket.
Lubricate blower motor
If the fan is loose, you will want to lubricate it so that it makes less noise. Move the fan back and forth slowly and apply a thin layer of oil to the bearings with your hand or a rag. Move the fan again to work any extra oil into the bearings, and then wipe away any excess oil with a paper towel or rag.
Adjust belts for proper tension
If your furnace is humming but there is no other noticeable issue with the unit, then you may need to adjust the belts on your blower motor. Over time, the belts can become loose and cause a humming noise when they are running. The belts can be tightened by moving them from one motor pulley to another, or you can purchase a new pair at an appliance store.
Make sure blades are balanced
If your furnace blades are unbalanced, then it will cause a humming noise to emanate from the unit. Use a pair of pliers to slightly bend the blade away from the heavier side so that it is more balanced and will spin with less noise.
Replace belts and belts
It’s possible that your belts have become frayed and are causing more friction than they need to. You might not notice this issue until your new ones start wearing down quickly. Then, you may need to replace all the belts on your unit to ensure that they are no longer causing noise. Be sure to keep the original belts in a safe place so that you can make a new set of replacements if the need arises.