Furnace blower bearings must be replaced as the unit ages and succumbs to normal wear. While it does require dexterity, changing the bearings in a furnace blower is fairly easy for people with basic to moderate home improvement skills. Normal function in the furnace blower should resume as soon as the old bearings are replaced, so any further signs of trouble such as noise, sluggish air movement, and odd smells must be reported to a certified repairman as soon as possible to avoid damage to the unit.
Things You'll Need
- Flathead or cross-head screwdriver
- 1/2-inch or 7/16-inch end wrench
- Shallow tray or bowl
- Pipe cleaner
- Lubricating oil
Turn off power to the furnace before changing the blower bearings by unplugging it or by flipping the circuit breaker associated with the unit. Allow the body of the furnace to cool completely before commencing work on it.
Locate the removable back panel on the body of the furnace unit. Remove the screws using a flat head or cross-head screwdriver, depending on the make and model of the furnace. Pull off the back panel to reveal the blower motor, which contains the bearings. Consult the manufacturer-provided operation manual to help identify the blower motor.
Locate the mounting bolts that hold the furnace blower in place. Loosen them with a 1/2- or 7/16-inch end wrench depending on the size of the bolts. Carefully lift the blower from its housing and move it to a clean, well-lit work space. Retain all the removed bolts and screws for later reassembly.
Hold the blower above a shallow tray or bowl. Slowly turn it until the bearings reach the output hole located on the side and fall into the shallow tray or bowl. Slide a length of pipe cleaner into the blower bearing manifold and push it out the other side to ensure all the old ball bearings are removed.
Coat the new blower bearings in lubricating oil before inserting them into the blower. Insert them one at a time into the hole through which the old bearings were removed. Add the same number of bearings as were removed. Close up the blower unit and place it in its original position inside the furnace. Secure it with the previously removed bolts and reattach the back panel onto the furnace.
Tips & Warnings
- Always defer to the manufacturer-provided operation manual when performing maintenance on furnaces to avoid the possibility of injury or a void of warranty.
- Forced Hot Air Furnaces: Troubleshooting and Repair; Roger Vizi