Keeping the blower assembly on your furnace clean helps improve performance and efficiency by allowing the air to flow unobstructed. The process requires a number of steps, and you might want to call in a professional to do the job. If you choose to do it yourself, here’s the procedure.
First, turn off the power to the furnace. This should be done at the fuse or breaker box. Then turn off the furnace and fan switches inside the unit. Also switch your thermostat off.
Second, take the blower assembly out of the furnace. To do this, you have to disconnect the fan motor wiring harness connector. Make sure you make your own schematic showing how the wires run before you perform the disconnection.
To remove the assembly, take out the screws; then slide it out. Make sure you don’t touch the terminals of the capacitor, which is probably connected to the side of the blower assembly. There may be some refrigerant lines in this area. Don’t bend them so they crimp.
Third, if the capacitor is attached to the blower housing, discharge it and take it out. If you can’t find the capacitor, it probably isn’t required on your unit or is located somewhere else in the furnace, so you can move on to the next step.
If you do find the capacitor on the side of the housing, remove the wires with a pair of needle-nose pliers. Make sure they have an insulated grip to prevent electrical shock. Also, do not touch the terminals.
You can discharge the capacitor using a resistor-type jumper. If you don’t know how to use a jumper, call a professional. When the capacitor is discharged, go ahead and remove it.
Fourth, take the motor and blower wheel out of the housing. Mark the spot where the hub sits on the fan shaft because this piece must be replaced in exactly the same spot.
To remove the wheel, loosen the setscrew. Then turn the housing over and remove the motor bracket bolts. Turn the housing back over and, with a piece of two-by-four, softly knock the motor and shaft out of the wheel. Also remove the deflector portion of the housing by removing the screws.
Finally, clean the blower wheel and the fan motor. It’s easiest to use a spray wand at the car wash to clean the wheel, but don’t direct the water at the wheel at full pressure to avoid bending the fan’s fins. You can clean the motor with a soft brush (no water).
Keeping your furnace blower assembly clean can mean lower energy bills and a more comfortable home.