How to Service the Blower Fan on a Tempstar Furnace

Disrupt the power supply to your Tempstar furnace while servicing the blower fan or other internal components. Remove the corresponding fuse from your fuse box or flip the circuit breaker switch to "Off." Turn the gas valve clockwise several rotations to close it.

Remove the top door on downflow furnaces, or the bottom door in upflow models, to access the blower compartment. Unfasten the screws securing the appropriate access door with a screwdriver; the type and number of screws varies by furnace model. Pull the blower compartment door away from the front of the furnace cabinet and set it aside.

Take out the screws mounting the blower assembly to the top or bottom of the blower compartment using the screwdriver. Pull the blower assembly toward you; the assembly slides out on rails for easier service access.

Remove the furnace filter from the blower compartment. Clean washable furnace filters and discard disposable ones. For best results, clean or replace the blower compartment filter every two to three months.

Vacuum the inside of the blower compartment using a vacuum cleaner with an attachment. Make this a regular part of your blower fan maintenance to prevent dust, lint and other grime from building up inside the compartment.

Turn the blower assembly on its side so that you can assess the blower motor. Touch the motor capacitor with the tip of a well-insulated metal screwdriver to discharge it. Set an ohmmeter to measure Rx1 resistance and place one probe on each of the capacitor terminals. Replace the capacitor if the ohmmeter fails to register a reading. Touch the ohmmeter probes to the motor's common and run windings, then the common and start windings; the ohmmeter should show a resistance reading for each test. Replace the blower motor if you receive a reading of infinity for either test.

Remove the bolts and washers securing the blower motor to the blower assembly using the adjustable wrench. Lift the motor out of the center of the blower assembly and set it aside.

Pull the squirrel-cage blower fan out of the blower assembly; you may have to unfasten a few mounting screws or bolts, depending on the design of your Tempstar furnace. Wash the dirty blower fan in your bathtub or vacuum it with a soft brush attachment. Wipe each blade clean with a sponge moistened in warm, soapy water, if necessary. Allow the squirrel-cage blower fan blades to dry completely before reinstalling them in the blower assembly housing.