How To Replace a Furnace Blower Motor and Capacitor

By | September 16, 2020

How To Replace a Furnace Blower Motor and Capacitor 44
A furnace blower motor can be replaced by a handy DIY homeowner which can save money.

Of course, if in-doubt be sure to call a professional HVAC technician.

A new motor and capacitor will need to be bought to replace the old unit.

Most hardware stores will not carry a furnace motor but a new unit can be bought easily online on Amazon or eBay.

Example Furnace Blower Motor on Amazon
A1588, 1/2HP 230V Air Handler Motor, 1075RPM, 3.2AMP

Read Here For How To Buy a New Furnace Blower Motor and Capacitor

How To Replace a Furnace Blower Motor and Capacitor

  1. Turn the power off to the furnace.
  2. Be sure to turn off the power to the furnace or unplug it before any work is done to a motor or any components.

  3. Locate the furnace blower motor.
  4. The first step is to locate the motor which is the only large motor in the furnace.

    Here is a furnace motor assembly and capacitor bolted onto the assembly.
    How To Replace a Furnace Blower Motor and Capacitor Step 2

  5. Locate the Furnace Capacitor.
  6. Look for a Start or RUN Capacitor since this will also have to be changed (if the furnace has one). A bad or failing capacitor can damage a new motor so it must be changed any time a new motor is installed.

    Some furnaces don’t have a RUN or Start capacitor which can vary between units.

  7. Take pictures of the blower motor and capacitor.
  8. Before anything is removed or any work done take pictures and write down all the wiring and connections.

    Take good pictures or a video to refer back to later if needed. If something is wired wrong the motor may burn up or at the very least not work. Having pictures to look back at can be invaluable when reconnecting everything.

    Once you have good pictures of the wiring, the wires can be unplugged and removed.

  9. Remove the blower motor assembly.
  10. The motor will be inside of a sheet metal assembly making it necessary to remove the entire assembly.
    How To Replace a Furnace Blower Motor and Capacitor
    Screws holding it in are usually located in the front with a notch in the back it can slide out of.

  11. Remove the fan blades.
  12. Once the entire assembly is taken out the bolts holding the fan blades in place need to be removed.
    Replaceing a Furnace Blower Motor and Capacitor
    One bolt will hold onto the shaft and needs to be loosened to slid off.

    To remove it loosen it up so that the shaft can pull out from the fan blades. It is a good idea to oil up the end of the shaft so it pulls out easier as some can be a pain. If there is any rust or build up on the shaft use sandpaper to remove it then oil it. Otherwise pulling a motor from the fan blades can be very hard sometimes.

  13. Remove blower motor bracket.
  14. Next, the bolts holding the back of the blower motor should be removed and the motor pulled from the fan blades.
    How To Replace a Furnace Blower Motor
    On a side note, it is a good idea to clean the fan blades when the assembly is out. Debris build up on fan blades make them work less efficiently cleaning them is always a good idea. If the fan blades are really dirty take them to a car wash and after spraying them with de-greaser power wash them.

    The motor will have a ring that goes around it and bolts to the housing, this should be taken off the old motor and put one the new one. In some cases it can be damaged if it has been a new one can be bought.
    Furnace Blower Motor Bolts
    Once the ring has been placed on the new motor the shaft can be slid back on to the fan blades and bolted into place.

    Example Replacement Furnace Motor Bracket On Amazon.
    Dayton Motor Mtg Bracket, 3-Ring, Anodized Steel – 2MEV2

  15. Bolt the fan blades back into place.
  16. When bolting the fan blades in they will need to be centered so the blades spin freely in the housing.
    Furnace blower motor spin freeley

    Before tightening the bolt on the shaft be sure it is centered correctly since there is a flat spot on the shaft that is where the bolt screws into holding it in place.
    Furnace Blower Motor Shaft

    Before installing the assembly back into the furnace be sure the fan blades spin without hitting the housing.

    Remember to connect the ground wire to the case.
    Furnace blower Motor Ground Wire

  17. Install the new capacitor.
  18. Install the new capacitor and connect the correct wires from the motor.
    Furnace blower Motor Capacitor Replacement 22

  19. Double check the assembly.
  20. Double check everything is connected and the fan blades are spinning correctly and it will be time to reinstall the assembly back into the furnace.
    Furnace Blower Motor Swap

  21. Install the assembly back into the furnace.
  22. Installing will simply be the reverse of taking it out. The hardest part is often getting it to slide in correctly into the metal tabs.
    Furnace Blower Motor Installation

  23. Tighten the bolt holding the assembly in place.
  24. After getting it back into place tighten it in with the holding screws.
    Furnace Blower Motor Installation 33

    After getting the assembly back in double check the fan blades again for proper spinning. You don’t want to damage anything when power is applied and they spin fast.

  25. Reattach the wiring.
  26. After the assembly is back into place the wiring can be reconnected. This is where the picture taken earlier comes into play.
    Furnace blower Motor Capacitor Wiring
    If there is a wiring problem look at the schematic for the furnace.

  27. Test the blower motor.
  28. Turn the power back on. It is always a good idea to double check everything before turning the power back on.

    Once the power is back on and the thermostat set the furnace should kick on and blower motor spinning.


 




 

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.