Intertherm/Nordyne MGH-075 blower problem

darwynduck · Tue Jan 05, 2010 2:25 pm

Here is the situation that I am having with my furnace and it has been going on for months now and is getting progressively worse. When the furnace comes on, the blower sometimes starts and sometimes doesn't. When it doesn't come on, it makes a humming noise and if we go spin the fan, it starts right up and runs and shuts down as it should. We have watched the fan to see what happens when it doesn't start, and it actually goes a "tick" backwards and then won't go on its own. We tried a new limit switch with no improvement and have also tried oiling different parts of it which has made a small improvement. I am thinking that we need a new blower motor (it is 20 years old), but do not want to spend the money on that if it is not the part we need. Any suggestions? Thank you!

raydizzle34 · Fri Jan 08, 2010 2:50 am

Sounds like it could just be your run capacitor. Robert could get a part number for you.

darwynduck · Fri Jan 08, 2010 10:19 am

Is this a hard part to replace? We had a heck of a time with the limit switch, as it wasn't an exact replacement and had to do a ton of rewiring. Thanks!!

raydizzle34 · Fri Jan 08, 2010 12:53 pm

Should just need a nut driver to remove the screw that holds it in place and there are only 2 wires going to it so it shouldn't be too difficult. The wires come directly from the motor.

raydizzle34 · Fri Jan 08, 2010 12:54 pm

it looks something like this.

http://www.mobilehomerepair.com/media/i ... 621433.jpg

darwynduck · Fri Jan 08, 2010 3:54 pm

That sounds great! Which part number would I need for my model of furnace? So you think that will alleviate the problem that we are having? Thanks again!

raydizzle34 · Fri Jan 08, 2010 9:54 pm

If you turn off all the circuit breakers that power the unit and pull the blower motor section out, you should be able to remove the run capacitor and see what rating it is. It will be a number like 5, 10, 12.5, 15, or 20 followed by uF. When you have this number, you will be able to either order it online or find a local parts house that you can purchase this part from. If anything I would send Robert a message and ask him for the part number.