Heater fan repair

Assuming it's the typical shaded pole motor,

It's best to remove the fan blades and disassemble the motor to remve the shaft from the bushings.

Then. clean out the gummed up bushings and the shaft, put a couple drops of electric motor oil on the shaft and bushings, reassemble in reverse order.

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My experience with these motors is that relubes don't last nearly as long as the initial period before the fan started binding. I've tried everything from 3-in-1 oil, sewing machine oil, teles oil, silicon oil, PTFE fluid, WD-40, etc.. Same story with all. I presume this is due to the sleeve bearings wearing such that the shaft is allowed to wobble/shutter. Or perhaps the factories use a highly specialized lube just for these motors.

Also, Roger, if this is the shaded pole motor Sam and I are assuming it is and it has the stamped blades with rubber coupler, you must get the blades reinstalled just right or the imbalance will cause annoying vibration/rattle which also happens to add to the wear on the sleeve bearings.

Just take it apart and put a few drops of sewing machine oil, 3 in 1 oil, or something similar on the shaft at the bearing and twirl it a few times by hand to work the oil in then reassemble.

Often they use porous bronze bushings which should work better if soaked overnight in a cup of oil. I've found that automotive wheel bearing grease works well when other oils don't as it's thick and sticks on it's own.

If they are a press-fit, you may be able to do this with the blades in place if there is enough exposed shaft.

I do have to lube my 50+ year old heater fan every couple years.

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I notice the same. I find motor oil works pretty good. I use SAE30 from the lawnmower, but 5W30 or 10W30 from a car should work too (but would be thinner at 'low' temperature).

Thanks to everyone who posted suggestions. They all seemed good and encouraged me to try lubrication.

It was not possible for me to remove the fan blade without doing damage I couldn't repair so access to the motor shaft was difficult. Then I noticed there was a plug in the heater case that was easy to pop off, and under the plug was the other end of the motor shaft.

First I tried 3-in-1 oil, and that made the fan feel less stiff, but under power it didn't rotate fast enough. I then tried WD-40 and that worked great. The fan now turns at full speed and the heater appears to be working properly. Let's see how long it lasts.

Thanks again for the help. This is a great group.

The WD-40 won't last too long since it's not a good lubricant.

You'll want to clean up any WD-40 you can get to and then use real oil. Almost anything is better than WD-40. :) WD-40 is only for immediate gratification assuming someone else will have to deal with the consequences down the road.

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The wd-40 is good for flushing out the old dried up lube, but you'll want to stick some good oil in there after that. Also you have to be very careful using something as flammable as WD-40 in a heater, you've already powered it up but normally I'd say make sure it's well ventilated first.

As others have suggested, WD-40 isn't the best bet, especially where the motor will be exposed to higher-than-usual heat. The heat will get rid of the WD-40 jiffy quick. I bet it also stinks to high heaven -- not a super good idea to breathe the fumes, either. For high-heat applications, you might go with silicon oil or PTFE (teflon) fluid.

If you now have both 3-in-1 and WD-40 in there, expect it to last an even shorter period. The WD-40 breaks up the oil and it will gunk it up in no time (the heat helps this along). Before trying the next lube type, clean the motor thoroughly and only use ONE lube type at a time (i.e., don't mix lubes).

The fan most likely has either brass or steel one piece bearings.(single ball that the shaft sits on and is nested in a mount that has felt type oiler pads.)

3-in1 makes an small electric motor oil(sae 5-10w??) that you can get at most any hardware store that'll do the trick. Just put a drop or two on the shaft letting it run down into the bearing and onto the felt pads. Be sure to oil both front and rear bearings. Another brand of oil goes by the name of "Zoom Spout oiler" and can be had at your local Ace hardware store. It comes in a white plastic bottle with a pull out plastic drip tube, is a pure turbine oil and is perfect for lubing those heater blower bearings.(Made by Norvey inc of Santa Ana.) Sometimes the bearings will be gummed up with dried oil and gunk and willl need to be removed and cleaned to get the best results.(usually a couple of retainer screws on the bearing collars and the whole assembly will pull apart allowing removal of the bearing from the shaft. It can be cleaned with just about any solvent, I use a good brand of carbuerator cleaner myself.(just spray the bearings and wipe with a lint free shop rag.) Be sure to oil all mating surfaces lightly before reassembly.(be sure to saturate the felt oiler pads as well.) If the bearing is of the steel variety you can use a good grade of teflon grease instead of oil, just coat the shaft and bearing surface lightly.(brass bearings tend to absorb most of the oils from the silicone which will result in the grease gumming up in the long term.)