Original message
| kloster
 |  "Blower motor"
, posted Mon 15 Dec 14:59  
I woke up in the middle of the night yesterday because there was a burning smell in the bedroom, the kind of smell you get when there is an electrical short. I couldn’t find the source of the smell until I checked the furnace room in the basement. There was no smell in the room (it probably drifted upstairs) and the furnace wasn’t on but the humidifier was running – it normally shuts off when the furnace shuts off. I also checked the blower motor and found it was very hot. Obviously it was getting power but was not turning. I thought it had seized and I’d have to get a new one. I turned off the power to the furnace, waited a couple of hours and turned the power back on. The furnace started fine and then the blower kicked in, also without any noise or vibrations. The furnace and the blower seem to work as good as before.
I am puzzled as to why the blower would seize or stop working and be OK after power was turned off for a period of time. Did I reset any switches by turning off the power? The furnace is a 15-year-old Lennox (68Q3-120). Also, the blower motor is direct drive and when I enquired at a service shop few years ago whether it had to be lubricated I was told that direct drive motors don’t need lubricating, so I never did. However, yesterday when I was inspecting the blower motor I found a tiny white plastic plug in what is definitely a lubricating hole. I put in a couple of drops of oil but am not sure how much is enough or too much. Could the reason for the burning smell be the fact that the motor hasn't been oiled for 10 years?
John Kloster
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Replies:
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| David7777777
| "RE: Blower motor" , posted Tue 6 Jan 15:50
Opinion
Lets say that the motor shafts were getting dry. Also lets say that the brushes in the motor happen to stop on a rough spot. Maybe that was your warning. If it was me, I would keep an eye on it. As soon as possible, I would take that motor out an open the motor up and see how it looks. Something is telling you that this does not make sense. Listen to your instincts. I am guessing that whatever caused that problem will cause it again. Might as well check it out on your schedule instead of waiting until the middle of some cold night. If that motor got hot enought to smell up the house, then to me it bears looking inside of the motor to see how it is.
Always wanting to learn from good people.
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| xenos
Webmaster 
| "Re(1):Blower motor" , posted Mon 15 Dec 18:06
Yes you may have reset it if it was off on limit. Possibly the motor did require oil and a couple drops is enough. You may also want to check your filters.
Xenos.
The best way to escape a problem is to solve it.
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| | kloster
| "Re(2):Blower motor" , posted Tue 16 Dec 12:56
Thank you for your reply. I do appreciate it. I’m still wondering what would cause a blower motor to suddenly overheat and shut off. It was not under heavy load (the thermostat was turned down for the night) and it was running fine before – no noise or vibrations. The filter is clean. This is the first time something like this happened. The furnace is running well but now I’m worried that it will happen again on a cold -20C° night. Is it possible that the run capacitor is the culprit? Do run capacitors fail gradually over a period of time (so one gets adequate warning) or do they fail suddenly and that’s it? My blower motor has one 5 FMD run capacitor in good external condition (no leaking fluid). Thanks again for your reply.
John Kloster
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| | xenos
Webmaster
| "Re(3):Blower motor" , posted Tue 16 Dec 17:09
The bearings could be going. If there is play in them one of them could have moved slightly and locked up.
Looking at the shaft any side to side movement is a sign of a bad bearing.
Xenos.
The best way to escape a problem is to solve it.
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| | tj doitmyself
| "Re(4):Blower motor" , posted Mon 5 Jan 18:01
I have a Lennox G21Q3-60-1 The motor is shot sleeve bearing. I had the same problem this summer the blower would kick out and blew the fuse I waited to long and now I am looking for a new motor. :( Why do I need to pay Lennox 154.00 (includes cap and shipping) where can I find a reasonably priced motor it's only a 1/3 hp is there a cross over that will go on my blower?
It's 22 deg here Thank God I bought that add on wood burner
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| | xenos
Webmaster
| "Re(5):Blower motor" , posted Mon 5 Jan 18:51
Go to a local electrical motor shop. They can match one up for you.
Xenos.
The best way to escape a problem is to solve it.
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