I have a ceiling exhaust fan making noise and, squeaking at start-up. Are they standardized in size? Is installation complicated?
I have replaced the fan motor alone a couple of times. I think it is just a couple of screws and on mine it literally just plugged-in (with a standard appliance plug). Like this. Just have to find the right replacement for your model, no need to replace the entire assembly, I would gather.
I’ve installed or replaced several in the last few years, but I’m not an expert.
No, they’re not hard to install, especially if there is existing electrical wiring and exterior vent you can use. A new one takes me about an hour.
No, they’re not standard in size. If you can find a new one that fits into the old box, great. Twice, though, I couldn’t find the same model, so I installed one slightly larger and just trimmed the edges of the old opening to fit. It was simple.
You can easily find reducers or adapters to connect the new one to the existing exterior vent. If you need to extend the electrical wiring, just get a box and cover you can nail to the joist near the van and add some cable. (This assumes you can get to the old fan from your attic. It’s a bit trickier if your fan is in a first floor ceiling with a finished second floor.)
I had the same problem. I removed the motor and googled the model number, got a hit and bought a new one. I also could have tried a local business that specializes in electric motors but got lucky.
Much easier than trying to put in a new unit - which would have meant tearing out sheetrock.
Installing one fresh? It can be easy, or it can be a major PITA.
Replacing an existing one? Piece of cake!
Good point. To be honest, I’ve fixed a few fan (and other) motors from squeaking by putting heavy grease on the motor shaft. It usually lasts a year or so.
Agree with the others. If the fan is broken, you can get a new motor like the one linked to above. Home Depot etc will have replacements for the common ones.
This is a ten minute job and you’ll probably spend more time cleaning up drywall and toilet paper dust than anything else.
Replacing the entire unit, on the other hand, is at least a half hour job if you done it before, have access to the area above (ie attic) and the new one fits in the old hole. If any of those are different it’s going to be a much bigger project.
How old is the fan? Could be a LOT of dust up there.
The fan is of unknown age. The Townhouse was built in 1971 and, still has aluminum wiring in it.
You might see if you can find a low-sone (low noise) replacement. I know Panasonic makes them, but others probably do, too.
At that age, it’s definitely worth cleaning out the ducting while you’ve got it open. Also, get some weather stripping tape to seal the connection between the fan and the duct. Cheap duct tape will eventually allow moisture to get out into the void, dampening your joists and any subfloor above.
If the fan has aluminum wiring, check the termination points when you take out the motor. Aluminum terminations are much more likely to cause fires if not maintained well than copper termination points are.
It’s something I do occasionally. Not too hard.
The last time I bought one at HD it was cheaper to buy the replacement kit than the motor alone.
We replaced one. Home Depot sold us the wrong one which did not fit, but I found the right one on Amazon. We’re a couple of old ladies. 
I’ve fixed two of them (13 years old) recently. Pulled the motor frame out, cleaned it off, WD-40 to get it loose/free spinning, then some light oil (like sewing machine oil, or 3-in-1 oil). Put back in , runs fine. The aluminum wire doesn’t usually matter, they plug in with a regular plug on a short (6") cord. If that works, they do just fine.
Installing a new ceiling fan, especially if there’s already a cutout and exhaust hose, should be cheap and easy even if you pay someone to do it. And the newer fans are incredibly quiet. Last time I had this done I put in the cheapest model and it was so quiet I wasn’t sure at first that it was working.
I feel that a louder Fan would be better. Why hear the various bodily emanations when, someone is using the Bathroom? Anyhow, I was able to find a direct replacement Fan Motor Assembly and, it was a 5 minute job to replace. I thought it would be more involved. Thanks to all!
I’ve replaced several. I’ve replaced the motors on a couple. Putting a new installation is only a little more complex. If there is one there, I replace it with the same brand and size, or as close as possible. I hate doing any drywall, and doing ceiling drywall sucks the most.
It is an electrical code violation to conceal a junction box; just mount the new fan in the original location or fish a new longer cable properly from the switch box.
Speaking as someone who has to fix people’s renovation half-assery constantly.
A junction box in an attic is considered accessible. It might be annoying to get up into the attic, but generally as long as you don’t have to remove part of the building (ie cut into drywall, removing paneling, take up part of the floor etc), it’s okay. I believe they can even be buried in loose fill or batt insulation.
Now, you’re local AHJ may feel differently but in general the NEC allows it.