I have a bathroom fan that doesn't turn anymore. Flipping the switch doesn't do anything, but if I nudge it enough it might get going. I used to spray WD-40 on the bottom where I could see it turn and that used to be enough to get it going for another few weeks, but now it's really dead.

Any tips on replacing this thing? I've purchased a really simple replacement fan at Home Depot that seems to be about the same size. What I'm not sure about is what I need to take out of the existing hole where the fan is - are there any ducts or the like that are tricky to take care of?

I'm assuming the steps are something like so:

  1. Turn off all power to the bathroom
  2. Remove fan cover and unscrew everything I see
  3. (Detach ducts?)
  4. Put new fan in place of the old one and screw in everything I can see
  5. (Attach ducts?)
  6. Turn on power, pray, flip on switch to fan
  7. Success

Now, before I kill myself, is there anything else I need to be aware of? Do I need to crawl into my attic to detach/attach anything? I'm not even aware of what pipes lead where up there.

I'm pretty clueless with how this works, so apologies if I left out any critical information. I'm guessing that it's pretty standard stuff, but I'm completely unfamiliar with the whole territory (I don't know what I don't know, and all that).

  • 2
    FYI: WD-40 was probably not a good idea, more than likely it did more harm than good. I'm sure it will lube things up for a bit, but then it just acts as a binding agent to hold crud together.
    – Tester101
    May 17, 2011 at 21:40
  • Do you have access to the fan from the attic? if not you may find it difficult to connect the wires and/or exhaust pipe, depending on how much slack the installer left.
    – Tester101
    May 17, 2011 at 21:44
  • I can indeed get into my attic. I guess I'll do it from that end if I have to then. May 17, 2011 at 22:21
  • Your explanation looks A-OK to me; you'll probably want to do this from the attic, though.
    – Dean J
    May 28, 2011 at 13:08
  • I ended up doing this from the attic. Aside from it being a PITA crawling around up there, I was successful. My only post-OP concerns are that the duct could come loose from the new fan (I don't think it is - I should have used hose-clamps on the duct instead of just tape), and that the new box doesn't quite fit the current hole (I duct-taped the gaps over). Jun 24, 2011 at 19:58

4 Answers 4


If you have the option, I think it's easier to connect the wiring and ducts from the attic side. If it was installed during construction, they did it without the ceiling in place, so you may find that the screws/nails to remove the enclosure cannot be accessed from in the bathroom. Make sure you get a tight fit with the drywall, otherwise you'll be sucking dust and dirt from the attic into the fan. That's all I can think of to add. nmc's link covered pretty much everything else.


If you have an existing fan, you should be able to replace the motor only. Turn off power, remove faceplate, unplug motor. Remove motor. Install new motor, plug in new motor. Turn on power and test, replace faceplate.

A picture of the housing your fan is in would help a lot.

  • It's worth a try, take the old fan to the store to see if you can find a match. But I've never been lucky enough to find an exact match with the same wiring, fan size, mount points, etc.
    – BMitch
    May 17, 2011 at 21:53
  • I don't have a picture handy, but I'll give it a shot. I was (probably unrealistically) thinking that these things sorts of things came in standard shapes and sizes. I already have a replacement fan that I sort of bought on-the-spot with little research, but I'll unbox it and see if at all resembles what's in my ceiling. May 17, 2011 at 22:22

I had a fan that was also having a hard time starting to spin. Inside the light fixture, the fan/motor assembly was plugged into a small outlet within the box, which along with a couple of screws made it easy to remove the fan.

Once that was out, I was able to clean lint out of the motor and add a few drops of lubricant oil where contact was being made. At this point there was a noticeable difference in how easy it was to turn the fan by hand. After putting the entire assembly back in place it spun better than it has in years. Cheaper than buying a replacement fan, and definitely easier than replacing the full box by avoiding wiring/ducting work.


See this video How to Replace and Install a Bathroom Ventilation Fan


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