How to Tighten a Furnace Blower Motor

What You'll Need
Hex wrench
Blower belt

Furnace blower motor malfunctions can become costly if repaired by a professional. However, with a little know-how, you can save some money and do the work yourself, especially in the case of small repairs. 

Step 1 – Turn Off the Power 

For safety reasons, turn off the power to the furnace. 

Step 2 – Realign Motor and Pulley

To see if your motor and pulley are in alignment, first position a square adjacent to the outer faces of the two pulleys. If they are not in line, first make sure the motor is securely mounted. Loose motor mounting bolts can cause the motor to be out of alignment. You can tighten them with a wrench; if you pull back on the motor after tightening them slightly, you’ll add tension to the belt. Then you can tighten the bolts entirely and the belt will work properly in coordination with the fan. If it’s the pulley, use a hex wrench to loosen the setscrew so that you can move the pulley in and out. 

Step 3 – Change the Belt 

Check your blower belt to be sure it isn’t frayed or worn in any way. Belt-driven blower motors call for accurate belt tension to run properly. Keep one on hand in case you need to change it. 

Step 4 – Oil the Blower 

Good maintenance on a furnace blower, whether it is a direct-drive motor or v-belt-and-pulley system, is always beneficial in avoiding malfunction. Find the lubrication ports on the motor and pulley and spurt a few drops of a non-detergent oil into them. Do this before each season (heating or cooling) begins.