When it comes to replacing
or repairing anything in your house, you might opt for a DIY approach. Even
with your furnace blower motor, you can easily replace it yourself if you have
basic handyman knowledge. If you call for an HVAC professional, it will cost
you couple hundred dollars for a standard service. But with our furnace blower
replacement guide, you can save money and do the replacement yourself.
This guide is for modern
furnaces with direct drive blower motors. In the case of a belt drive blower,
the replacement procedure is not the same. You have to first identify your
motor and proceed to select a new motor to replace.
How to diagnose a
faulty blower motor
Shut off the power of your
furnace, and using your hand, try to spin the blower. If it does not spin
freely, examine the oil ports. If you notice the oil ports are clogged, try
adding a few drops of oil to check whether it helps the motor spin properly.
But if you cannot find any port or the motor does not spin freely even after
putting in some oil, it means that the motor has to be replaced. Remember to
check the wires of the motor connections along with the run capacitor. If you
switch the power and turn the fan on, check if the blower spins freely at full
speed. If not, shut it off again and continue with replacing the furnace
blower.
How to remove the old
motor
First, write down or take
a photo of the wire colors and where they're connected before you disconnect
them. There is a separate wiring control box for most furnaces that contains
the wire connections and a relay. For updated models, the wires are connected
by spade connectors to a control board. For the next step, remove all the nuts
or bolts holding the blower in place with the furnace. Usually, you will find 2
or 3 bolts to unbolt in front of the blower assembly. Remove the remaining mounting
bolts that attach the motor to the housing. Once all the nuts are removed, pull
out the motor carefully. You should also remove the mounting bracket and
remember how it was placed so that you know the orientation while replacing
it.
6 things required
for replacing a motor
You have to select the
correct replacement motor. Usually, you can find a universal replacement if you
cannot find the exact replacement motor.
These are the 6 things you
need to know to find a replacement motor:
1.
Direct or belt type of drive
2.
Motor diameter in inches
3.
Voltage (208-230)
4.
Horsepower (1/2, 1)
5.
A belly band
6.
Run capacitor
Installing a new blower motor
The installation part is quite easy. It is practically the reverse of the removal procedure. After you remove the old one, secure the wheel of the new motor in place. Make sure to center the motor in the housing to ensure proper placement. Then you have to rotate carefully. Make a note of the right direction when you're removing the old motor. Once you put the new one, place the mounting bracket and start fixing the bolts in place. If any unused motor leads remain, you have to isolate them separately using electrical tape or wire nuts. It is advised to replace the old run capacitor while replacing the old motor. Once you secure all the bolts, switch on the power to check the normal operation of the furnace. If it makes no weird noise or the air comes out of the supply registers properly, you can conclude that the replacement is successfully completed.
Conclusion:
The furnace blower motor
is an important part of your system, so be careful to fix any repairs or
replacements whenever you notice an issue. If you see that your furnace is
malfunctioning or isn't turning on, you have to try to diagnose the problem
soon. If you are unable to figure it out on your own, you better call for the
technicians. Either way, be mindful of solving any issues with your furnace to
avoid bigger problems in the future.
See the summary of this
content here in an infographic – How
to Replace Furnace Blower Motor [Infographic]
