My bathroom exhaust fan didn’t work — and I find out why

Last week, our electrician installed a new bathroom exhaust fan in our green hall bath. During the install he made a shocking discovery — the old fan hadn’t worked properly since day-one. It was doing nothing. Zero. Zilch. Nada.  Apparently this problem is somewhat common, so I made a video to help others learn about my bathroom fan problem and why it wouldn’t work.


Kates-bathroom-graphic3Since beginning construction on my retro pink master bathroom, the hall bathroom has been seeing a lot more action. We’ve never had guests complain about the moisture issues in there, even though we knew they existed. But when we started using it full time ourselves, we realized just how bad it was. So when the electrician returned to finish working on the pink bathroom, I asked him to install a new fan in the green bathroom too.

In case you don’t have time to watch the video, here’s the gist of my bath fan woes:

  • Before we began work on the pink bath, both fans vented into the attic instead of outside. That’s a code no-no these days. Also stupid, because you don’t want wet moist air pouring into your attic.
  • The fan in the green bath didn’t seem to do much other than sound like an airplane landing — our towels wouldn’t dry and funk grew back quickly on shower tiles as soon as four or five days after being cleaned.
  • As long as we were paying the electrician to come finish up our master bathroom work and vent that fan out of the roof, we had him replace and vent our hall bath fan at the same time, saving $$$ since he could do it all in one trip to our house and one trip into the attic.
  • When the electrician removed the old fan he discovered a problem that went back to the fan’s initial install: The damper that opens when the fan is on (to let air out through the ductwork), and then closes when the fan is off (to prevent back drafts), was stuck in the closed position. This meant that no air could be pulled out of the bathroom through the fan.
  • The reason the damper wouldn’t open was that when the ductwork was attached to the fan, it was mushed up against the damper, impeding its ability to function.
  • The old fan — probably installed in the 1990s — never did anything but use electricity to make noise for all that time.
  • Since the installation of the new fan, we’ve noticed a huge difference. The mirror is no longer completely fogged when we get out of the shower — in fact it usually has no fog at all. Also, our towels have been drying and there has been no “funk” regrowth since the last bathroom cleaning.

The moral of the story here — if you suspect the fan in your bathroom only sounds like it is working, it might be worth checking (or having a professional check) the exhaust vent. If the damper does not move freely, or there is an obstruction in the ductwork, your bath fan may not be able to do its job.

Read all of the stories related to my pink bathroom remodel project here.

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  1. lynda says

    I think people don’t value bathroom fans enough. I personally like the Panasonic brand and I tend to buy a bigger fan than recommended for the space. Fans and water softeners keep baths clean longer! Glad you solved another household problem.

    • says

      Based on experience growing up, I’ll definitely second the Panasonic fan endorsement. Very quiet and they way outlasted the consumer grade products available at Home Depot. As far as sizing fans goes, from what I remember the larger ones are sized for really huge spaces, and the smallest fans are already slightly overkill for normal sized bathrooms. (I stubbornly refuse to call a sensible bathroom small)

    • Kate says

      YES! The last house I lived in didn’t have a bath fan. I’m glad to have them now — especially when they work properly. I also bought slightly more fan than needed for the space…mostly because of the moisture problems I’ve been having in those bathrooms.

  2. Kristen says

    This got me thinking about how well our bathroom fan works (or doesn’t work) which we had installed only a year ago…I think we might have this very problem! Thanks for the post.

  3. Andi says

    We just had a similar revelation about our original 1952 bathroom fan. We also knew it was barely working (though producing plenty of noise), so during our recent tub-to-shower conversion—-which, as an aside, was just finished yesterday after 19 WEEKS of assorted mishaps!!!—-but I digress.

    We had the fan replaced early on in this project. It vented to the outside as it should have, but when the electrician removed the fan, he found the duct almost entirely blocked by an old bird’s nest!!

    I didn’t know about that until the new one was all installed and the work done, or I’d have kept the old one—I think it would have worked fine again with a cleaned-out duct!

    One thing I couldn’t get them to remedy (at least not willingly) is that the fan and the light are on the same switch, so if you want light, you get the fan. There are, thankfully, great vertical sidelights on my medicine cabinet, which I leave on all day, but it is annoying to have the noisy fan when you don’t need it. (It does work, though).

    Boy, we sure do learn a lot with these projects, don’t we?

    • Kate says

      Wow — a bird’s nest! That’s a new one. :)

      In my hall bath there are lights over the vanity so we can turn those on without the fan/light. In our pink bathroom, I had the electrician wire one switch for all the lights (fan light, over vanity and ceiling fixture) and then put the fan on a timer switch. He also made it so we could put the fan and light on the timer (or another switch) easily if we changed our minds later. Our last bathroom had like 3 different switches for lights and we would accidentally leave one on all the time…not anymore!

      • jan arnett says

        They make bathroom fans that have a dual control just like your living room fan or you could run a wire mold and surface mount another wire. {edited – consult with a pro}

      • Mary Elizabeth says

        Not new to me, Kate. We had the same problem with birds in our old condo. Small sparrows, especially, love to get into the vents for dryers, bathrooms, etc. It was very funny that it took us a couple of springs before we figured out where all the cheeping was coming from in our downstairs powder room. We finally saw the parent birds flying in and out of the vent flaps with worms in their beaks. Then, of course, we disconnected the fan rather than kill the cute birdies! A simple solution is to install a wire cage over the vent so small animals–mice, birds, etc.–can’t get in.

  4. says

    Would you believe that neither of our bathrooms have a fan installed? I don’t know if that’s a flat roof thing or a dumb prior homeowner thing but we have no bathroom fans and likely no ventilation installed for them.

    • Jay says

      Depends on the building code in effect when your house was built. I assume you have operable windows or skylights in your baths which at one time was considered adequate ventilation. I grew up in a 1920s era rowhouse that had an old fashioned chain operated skylight over the tub.

    • nina462 says

      My 1965 ranch bathroom does not have a fan either – something I want to have installed. I just open the window when I take a shower (yes, even in the winter sometimes). If I don’t, the steam will set off the fire alarm…

  5. MattS says

    To test how well (if at all) your fan works, stick a single square of toilet paper up against it while it’s running. If it stays, the fan is doing at least the minimum it should. And I’ll third Panasonic, they make some quiet yet powerful fans.

    • pam kueber says

      ah, I am going to try this toilet paper trick. one of my new-ish bath fans never seems to be working well enough… thanks for the tip! i’m gonna go try this NOW!

  6. Renee says

    My house was built in 1955 and still had the original fan. The paint on the plaster walls in the bathroom was bubbled up, so we knew something was wrong. When we went up into the attic we found out it was ‘venting’ into a crossbeam….so basically it hadn’t worked properly in 53 years!

  7. Linda says

    I didn’t realize that venting bathroom fans into the attic was a widespread thing. We had that same issue in our 1965 house and it seemed so stupid. Not as lame though as the tub drain that was disconnected and just ran water under the house (that the home inspector did not catch!). *sigh* Love our “project house.”

    • Adrienne says

      I once owned a top floor condo in a historic building and started to notice mold spots on my ceiling where the studs on the beams would be. Turns out all 10 of the top floor units had bathroom fans venting directly into the attic, which was filled with moisture. Apparently they had been venting into the attic for a LONG time. All of the ceilings on the entire floor had to be ripped out.

        • Mary Elizabeth says

          Yes, when my DH was working as a handyman he found a least 50 bathroom fans that were venting into attics, some from relatively new construction. The owners would complain when the fan seemed ineffective or when they saw mold growing on the ceiling! It is against code in our area, but it sometimes happens when the plumbers, HVAC guys and the roofers don’t coordinate. A similar thing happened with our range hood in the 1959 house, which used to vent through the roof, but was covered over by the roofers, who didn’t tell the owners. Since no one was living in the house at the time and using the stove, no one had thought to check the vent. So for the first few weeks, the hood rained water and cooking grease back down on the stove. Eech! So my husband did a quick check of the roof and found no vent there.

  8. Sandra says

    Note: You can check the damper from inside–no need to go into the attic. I sometimes take the cover off and get a vacuum up there to vacuum out the dust, grease the fan spindle (?) if necessary, or clean the grille. Sometimes you can see a place to unplug it and some parts can be removed with 4 screws. I’ve brought fans back to life by cleaning them.

    The damper is above the fan blades so you may want to tape the fan switch OFF (especially if it’s on the light switch), and use a stick to push on the damper. It should be easy to push up and let flop down. Cleaning off dust can help it move better, seal better. From there, you can probably tell if it’s blocked by insulation or whether there is a duct protecting it. Sometimes it can get stuck open, and then you get spiders and dust coming down into the room from drafts.

    The only reason to go into the attic is to put in a duct or deal with something unusual.

    • Kate says

      Yes, good point Sandra. No need to go into the attic to check the damper….and keeping a fan clean also lengthens its life and helps it perform at its best!

  9. Nancy says

    We just this week had our bath fan vented outside as part of an energy upgrade. Ours took a long while to start up and was noisy and a mere metal louvred plate. With all the insulation work, our new audit showed a 47% improvement!

  10. DavidF says

    My parents rehabbed an old house where all the bathroom fans basically vented into the drywall; no ductwork, outside vents, nothing. We speculated on whether the work was done by a dodgy contractor who knew better or a do-it-yourselfer who didn’t.

  11. Maryanna says

    Our 1968 house has no fans at all in either bathroom. We would love to have one installed in each bathroom, but especially in the one that faces north, and so never gets any sunlight through its window. It has become so daunting to clean that tiny bathroom!

    We must be in the minority, because my husband and I both would prefer noisy fans. The “white noise” they create will add an extra level of privacy, especially in the Jack & Jill bathroom that is only accessible through the two smaller bedrooms. Any recommendations on non-quiet fans out there? :)

  12. lynda says

    In some houses it is hard to vent all the way to the roof. Panasonic makes through the wall fans. We have one that works well in a downstairs bath. Just thought this idea might help someone. Search for WhisperWall vent fan.

  13. Jay says

    Ah yes, the old fan venting into the attic. Good way to date your house construction. My hall bath with no windows vented into the attic. The master bath on an outside wall with window had no fan. The previous owner installed a fan in the master that was vented to the outside gable end via the attic but did nothing about the original hall bath fan. I subsequently had it ducted outside as well. I periodically go outside and look up to see that the appropriate damper has opened while each fan is running.
    But the previous owner did have separate switches installed for the hall bath fan to run independently from the light.

  14. says

    Oh and one other fan vent horror story – the kitchen exhaust fan vented into the den, which involved hacking a hole into the original 1951 Philippine mahogany V groove paneling to put a vent in. Now the fan is gone but the vent will forever be up at the top of that wall serving no purpose but to cover the hole.

  15. Robin, NV says

    Neither of my bathrooms are vented but both have outside windows. It’s fine in the summer when the weather is hot and dry and we can have the windows open but in the winter, it gets steamy in there to say the least. We don’t get any kind of mold or mildew problems because the humidity is so low here but I’m still adding bathroom fans to my long of things I want worked on.

  16. says

    A lot of times in home inspections of older homes, inspectors notice that vents are just venting up into the attic space and not actually outside of the home – not good. Everyone should peek up into their attic space and go outside and stare at your roof to make sure that all is done right. A lot of stove hood vents? The same thing. Just venting steam into an attic space and not outside.

  17. mary hershelman says

    Did you guys know that my vent was acting up this week. Good timing. Thanks for all the tips before I get the ladder out.

  18. A. W. Richards says

    We live in an apartment built around 1969-1970-ish. Fortunately, our bathroom has its original NuTone exhaust (stainless grille and all) and works great. If we ever have problems, I’ll be sure to let the maintenance guys know about this tip (cause I’d hate to lose that fan, it looks so darn cool).

  19. says

    We don’t have a fan in our only bathroom. We’ll probably get one when we find the “new” light fixture. Now we just open the window and leave the door open. Luckily it’s just the two of us! The only drawback is we often have curious cats watching us shower/bathe. :)

    I also just wanted to say that when you add any protrusions to your roof, like air vents, make sure it is properly “tied in” to your roof and there are no leaks. You might have to hire someone to do this, but it will be worth it to not have water damage a year later!

  20. Jennifer Kepesh says

    Our house, built in 1958 in a state that doesn’t worry that much about code, had three bathrooms, only one of which had a fan. We just demolished that bathroom. The second bathroom has a window. The master bathroom, just as tiny as the other two, has a skylight that doesn’t open. In the winter, we turn on the heater and that dries things up as it warms our toes, but in the summer–oh, well! The house is adobe; we have a flat roof, and I have no intention of getting rid of the skylight, so I guess we’ll just have to live with the consequences.

  21. Carl says

    We had the same problem in our bath…noisy fan, and when I went up into the attic to check on things, I found the usual venting into the attic with no ductwork at all. Replaced fan with a new Panasonic, and did the necessay ductwork (easy job,there was a vent out the top of the roof which just needed to be connected to the ductwork). Not especially fun to work in the attic in sunny South Texas, but such a nice change. Btw, your tub looks exactly like ours! Even the color….

  22. Kathy says

    I bought my 1970 house three years ago, and I had an exhaust fan installed in the bathroom. Can’t tell you how many professional people told me I didn’t need it, since I had a window in the bathroom. I put one in anyway and haven’t regretted it.

  23. Joel says

    I think a lot of the venting problems are because the workmen are thinking the problem the fans are supposed to solve is odor versus moisture. I had my house built in 1995 and was irritated to find the electricians had installed the vent fans in all the bathrooms over the toilets versus nearer the showers and tubs.

  24. Joe Felice says

    UBC requires a bath fan only if there is no window. If you have an older fan, check to see if it is thermal-overload protected. As a property manager, I have seen several fires due to overheating motors in exhaust fans. Generally, fans manufactured before the ’90s were not protected. All fans now are required to be. What happens is that the motor can overheat (especially if left on for extended periods), and then ignite the “gunk” which has been referenced here, or the insulation. You would be amazed at the amount of gunk that collects up there, on the fan motor, the housing and in the ducts. Lint, hair and dust accumulate, and, hair spray, being very sticky, binds them together and to the fan parts. Once coated, the motor easily overheats. It’s not a bad idea to remove the grill and vacuum out the housing area every so often.

    • pam kueber says

      Okay I’ll leave this comment as general guidance but REMIND everyone: Consult with a properly licensed professional of your very on on issues like these.

  25. Scott says

    Exact same thing here, all noise, no action. I’ve been blaming myself for the last decade or so that it was my fault for not spending enough on the fan to get a good one. Never considered it wasn’t installed or vented right.

    Great timing, I’m getting my bathroom painted next weekend! Three guesses what just got added to the list!

    • Scott says

      PS Kate I see the new fans are rated by Sones and CFM, is there a certain number I should be looking to be at or above to be sure the fan is effective?

          • Scott says

            Okay I got unlazy and looked up the terms at least, CFM is cubic feet per minute and Sones is a measurement of sound.

            Wish I kept the box for my old fan so I would know how much is not enough. :-)

            • says

              I had already decided on a Panasonic bathroom fan, and when I was trying to figure out how to size it I found a chart on their web site to convert volume of your bathroom (cubic feet) to required fan capacity (cubic feet per minute). Oversizing it won’t hurt anything except your wallet. I assume that this is per code.

              • Mary Elizabeth says

                Yes, Chad, we used those stats, too, when installing a fan in the bathroom of our new addition. The bath is only about 7 feet by 8 feet, but because of a last minute change in the roof design, the bathroom is tucked under a 14-foot slanted ceiling. Hence there are more cubic feet in that bath than the one with a flat 7 1/2 foot ceiling. And the fan works beautifully with all the proper venting, because my husband installed it in consultation with the roofer and siding people. Second Pam’s constant advice to consult with a professional or two when doing things like poking a hole in your roof or siding!

  26. Alice says

    Oddly, our 1957 rancher does not have exhaust fans in any of the four full baths, only in the 1/2 bath that does not have a tub or shower. That one vents into the attic. We don’t use it, but then, you generally don’t generate a lot of steam just washing your hands at the sink.

    What is amazing to us is that the other baths don’t get steamy, they are all wallpapered and the original wallpaper is still in tact and looking good to this day. No signs of mold, peeling, discolor etc. We can’t figure out how they engineered this to be the case. Each bathroom does have an HVAC intake and output vent.

  27. K slunder says

    We just bought an old house that has an exhaust fan in our bathrooms just like this one, but we can’t find the model numbers on them anywhere…do you know what model number and brand this one is listed?

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