How To Buy a New Furnace Blower Motor and Capacitor

By | August 31, 2019

How to buy a new furnace blower motor and capacitor
 
To buy a new furnace blower motor the old blower motor face plate will need to be looked at. The tag on the motor will say what horsepower it is, the RPM, Voltage, and amps.
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The model number can be used but in many cases old model numbers don’t match up to new ones. If you cannot find exact model number replacement then a universal replacement motor that matches the HP, RPM, Amp, Voltage, Speed along with shaft size will need to be bought.
 
If you can find a exact model number replacement then you are done you will simply need to order it.
 
If you can’t find an exact model number replacement then an equal replacement will have to be found. Motor manufactures make universal blower motors that can be wired to run at a wide range of settings depending how they are wired.
 
For example, you have a 1/2 HP blower motor and can’t find an exact model replacement you can buy a universal motor that runs at 1/4 HP,1/3, 1/2 HP depending on which wires from the motor are used.
 
Write down the following information from the tag on the motor when looking for a blower motor, then find one that matches your motor for a replacement.
 
Details Needed to Buy a Furnace Blower Motor

  • RPM: If the motor has multiple speeds then only the highest speed will be listed. Common motor speeds are 1200, 1075, and so on.
  • HP: 1/8, 1/3, 1/4, or 1/2
  • Amp: 5 uf, 6 uf, and so on
  • Voltage: 120 Volts or 240 Volts
  • Speed: 1 speed, 2 speed, or 3 speed
  • Shaft size: Most furnace motors use a 1/2 inch but sometimes they can be different.

Here is an example of a furnace blower motor on Amazon. You can see the listing description the specifications are listed for the motor.
 
Example Furnace Blower Motor On Amazon
A.O. Smith/Century DL1056 1/2 HP, 1075 RPM, 3 Speed, 115 Volts6.5 Amps, 48 Frame, Sleeve Bearing Direct Drive Blower Motor

 
Furnace Capacitor
Some furnaces don’t use a capacitor while others will have both a START and RUN capacitor. But most furnaces by far have a single capacitor.
 
Capacitors are measured in voltage and uf (micro farads). To find a replacement look at the capacitor and write down the Voltage (120, 240, 370, 440) and the uf (4-10 amps) and then order a replacement.
 
Here is an example capacitor that is 370 volts 5 uf.
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Any capacitor that is 370 volts 5 uf can replace this capacitor. The same will apply to any other capacitor simply match the voltage and micro farads.
(The part that says +-5% is what the capacitor is rated to go up or down from.)
 
Any capacitor that matches yours in voltage and amps will work.
 
Here is an example on Amazon, as you can see in the listing description it shows the uf and voltage.
 
Example Furnace Capacitor On Amazon
OneTrip Parts USA Capacitor 5 MFD – 5 uF 370 VAC Oval Replacement For Rheem Ruud Weatherking 43-25134-02


Where to Buy Parts
I like to buy my parts from Amazon and sometimes eBay, the parts are much cheaper compared to a HVAC supply store. If you are in a hurry then you can buy the parts at a HVAC supply store. Some don’t like to work with non HVAC people because of damaged parts being returned while others will not care. If you can wait a few days for parts to be delivered then I would suggest Amazon.
 

7 thoughts on “How To Buy a New Furnace Blower Motor and Capacitor

  1. Michael

    After compacitor was changed the blower started working for about an hour then started back doing the same thing as before it was changed……help

    Reply
  2. Andy

    I found a bunch of X13 motors, but mine is a variable speed. Will that work as long as HP, Volts, amps, etc match?

    Reply
  3. Dennie Griffin

    I have a blower motor with a 42 frame. Can I use a 48 frame instead as long as everything else matches up?

    Reply
  4. Lawrence Hall

    Blower drive motor failed after capacitor blew up no markings at all

    My option is to match up a capacitor to the motor or replace the motor and get new all
    best choice

    Reply
  5. Thomas

    Can I replace a 1/3 hp blower moter , Full-Load Amperage: 5.2, with a 1/2 hp motor, Full-Load Amperage: 8.4, that I have (new)?

    Reply
  6. R

    Is it acceptable to replace a certain power blower motor with a lower power universal motor? For example, replacing a 1/2 HP with a universal 1/4, 1/6, 1/8 HP? I understand a 1/2 HP can be replaced with a 1/2, 1/3, 1/4 by using the right wires to match the power, but what about the prior scenario? What would happen?

    Reply
    1. Rod S.

      The replacement must have at least the same hp as the one you are replacing. A 1/2, 1/3, and 1/4 hp motor has the capacity to produce 1/2 hp, which is what is required when replacing a 1/2 hp motor. The 1/4, 1/6, 1/8 hp motor has only half of the power required, so it will not be able to handle the load and will burn itself up very quickly.

      Reply

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