REPAIRED: Furnace blower not running properly (bad motor)

[BobTheBuilder]

I could not find these symptoms described on any of the threads. A few days ago the furnace motor sounded like it was not running properly and very little air was coming out of the vents so I shut it down. It continued to run through the cool down cycle (with the motor being slow) and then shut completely off. I restarted it after waiting an hour of so and the same thing happened again. I have tried this several times since and it always runs just fine and after maybe 5 minutes, you can hear the motor slow down. I have shut it down each time when this happens, it continues to run slowly for a minute or so (cool down cycle). If I try to restart it immediately, it will start running but the motor is slow. If it sits for a while, it sounds normal when started.

Does anyone have any ideas as to what might be going on?

Thanks!

 

[SNOKING]

Re: Furnace blower not running properly

Sounds like a fan motor bearing problem or possibly a low voltage issue. Do 12V lights dim also. Fan motor draws a lot of current. If you have a meter, watch the battery voltage. Might be a converter going South.

Chris

 

[danemayer]

Re: Furnace blower not running properly

Make sure you don't have any airflow restrictions inside.

 

[jerryjay11]

Re: Furnace blower not running properly

Sounds more like a capacitor problem. Bad capacitor won't allow the motor to get up to full speed. Or it could just be a bad fan motor.

 

[BobTheBuilder]

Re: Furnace blower not running properly

No, lights do not dim. I would think if it was an air flow restriction that it would not have the "pattern" that it has. Fan motor bearings sounds like a good possibility as a bad bearing could heat up and then bind.
I'll be gone and not at the computer but I appreciate the input and any others that want to chime in.

 

[BobTheBuilder]

Re: Furnace blower not running properly

Weather has dictated priorities other than the furnace but I am back on it and have another problem. Instructions for removal are to remove the 4 screws holding the vent cap first and then the 4 holding the main cover. The vent cap has SS (or chromed) Torx screws that are an odd size. None of my bits fit and I Googled to try and find the in-between size and could not find a listing for any other than 15 (too small) and 20 (too large).

Any help?

 

[JohnDar]

Re: Furnace blower not running properly

Odd that they didn’t use the #2 square drive screws like every where else. Could they be the same star drive like some wood deck screws? Looks like Torx, but isn’t.


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[BobTheBuilder]

Re: Furnace blower not running properly

I didn't know the deck screws were different but I have bits for them and I'll check when I get home. Thanks.

 

[BobTheBuilder]

Re: Furnace blower not running properly

One of the pics shows a Torx size 20 which will not go in the screw head and the other is a 15 that spins around. I cannot find any in-between sizes listed anywhere. This reminds me of the days of Chinese imports 40 years ago? Any ideas anyone? I am also trying to get info from Surburban.

 

[BobTheBuilder]

Re: Furnace blower not running properly

Suburban will not even talk to you about it--strictly refer you to service centers. Perhaps those screws are now odd sizes so you CAN'T take it out.

 

[TedS]

Re: Furnace blower not running properly

The screw heads may be double-square heads. Use a square driver.

 

[danemayer]

Re: Furnace blower not running properly

One of the pics shows a Torx size 20 which will not go in the screw head and the other is a 15 that spins around. I cannot find any in-between sizes listed anywhere. This reminds me of the days of Chinese imports 40 years ago? Any ideas anyone? I am also trying to get info from Surburban.

Bob, forget about those screws. Take out the 4 screws holding the larger cover. They should be #2 square heads. With those out, carefully wiggle the entire cover. The exhaust tubes under the funny screws will come out with the larger cover.

 

[CarterKraft]

Re: Furnace blower not running properly

One of the pics shows a Torx size 20 which will not go in the screw head and the other is a 15 that spins around. I cannot find any in-between sizes listed anywhere. This reminds me of the days of Chinese imports 40 years ago? Any ideas anyone? I am also trying to get info from Surburban.

I got this T-shirt...

The screws as I recall are 8 point not Torx, you use the #2 square to get them out. The
"star" appearance fooled me.

 

[JohnDar]

Re: Furnace blower not running properly

Now seeing the photos of what you’re talking about, Dan is right. No need to remove that vent cover, just remove the four screws holding the main cover.

I did mine last summer to correct a small gas leak due to a loose fitting (after having the furnace serviced).


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[BobTheBuilder]

Re: Furnace blower not running properly

Thank you Ted! Square driver was a perfect fit!

Suburban will NOT sell you parts as they don't want the liability of selling untrained individuals parts to repair a gas furnace (I get it). However, I found a source to buy parts including the replacement motor which I am pretty sure is the issue
https://pdxrvwholesale.com/contact

Cost with shipping was less than $100.

 

[BobTheBuilder]

Re: Furnace blower not running properly

My prior posts told of my problem and source I found for a motor. I also found a service manual (the gas people don't want you neophytes to have!!) and have submitted it for inclusion in the manuals.

There is info on removing the furnace but not on how to remove the motor. It took about 2 hours and the hardest part was working parts from under the wiring harness as it is tight. But once I had it out--it was straight forward.

AND, the furnace works perfectly--it was the motor. Less than $100 repair.

 

[jbeletti]

Bob - happy to hear you got your furnace going. Great that you found a source for the blower motor and had the skills to do the work yourself.