How to Inspect the Blower-Fan Belt on a Furnace
Regularly inspect blower-fan belts for any sign of damage and replace the belt if it’s damaged. Knowing how to inspect the blower-fan belt improves furnace efficiency.
Furnaces need monthly maintenance and many do-it-yourselfers overlook the blower-fan belt. A worn, wimpy belt isn’t dangerous, but it makes a squealing noise that may drive you crazy and, more important, cost you money. If the belt isn’t tight enough, it slips, and the fan won’t turn as it should. You get less hot air for your money.
Inspect the belt for wear and tear. Look for signs of cracking or weakness. If the belt is frayed or looks worn, replace it right away. In fact, as long as you're buying a new blower-fan belt, buy two. Keep the extra one in a plastic bag on a nail by the furnace for those middle-of-the-night, all-the-stores-are-closed, the-house-is-freezing, blown-fan-belt emergency.
Check the tension. Even if the belt looks good, if it has more than 1/2 inch of give either way (1 inch total), tighten it by taking up the extra slack by using the motor adjusting bolt.
Don’t tighten too much — a too-tight belt damages the motor and fan bearings and makes a big, expensive mess of things.
Adjust the pulley alignment. While you’re in there fooling with the belt, check the pulley alignment too. The pulleys should line up perfectly. If you see any twisting in the belt, loosen the motor pulley mounting bolts and make an adjustment.