How to Install a Bathroom Fan with Old Wiring | Ask This Old House

In this video, This Old House master electrician Heath Eastman makes a house call to help a homeowner add some ventilation to their bathroom. But due to the age of the home, he’s worried about the age of the wiring.
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Updating bathroom ventilation isn’t usually all that big of a deal. But in an older home, the outdated electrical system and lack of an existing vent system can make it tough. When a homeowner wanted to add ventilation to her older home, master electrician Heath Eastman was the pro for the job, and he took us along for the ride.
Where to find it?
Heath installs a remote motor bath fan [homedepot.sjv....] in the attic above the bathroom.
To cut a hole in the ceiling for the exhaust grille, Heath uses a 6” hole saw [homedepot.sjv....].
For the new switcher, heath installs a timer switch [homedepot.sjv....] that has the option of setting the fan for 10, 20, 30, or 60-minute increments.
The sheet metal technician installs 4-inch ductwork [homedepot.sjv....] which connects from the damper [homedepot.sjv....], to the remote motor, then out the exterior of the gable end.
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From the makers of This Old House, America’s first and most trusted home improvement show, Ask This Old House answers the steady stream of home improvement questions asked by viewers across the United States. Covering topics from landscaping to electrical to HVAC and plumbing to painting and more. Ask This Old House features the experts from This Old House, including general contractor Tom Silva, plumbing and heating expert Richard Trethewey, landscape contractor Jenn Nawada, master carpenter Norm Abram, and host Kevin O’Connor. ASK This Old House helps you protect and preserve your greatest investment-your home.
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How to Install a Bathroom Fan with Old Wiring | Ask This Old House
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[@beng3345]

As usual, perfect access.

[@nickthompson7369]

Why is every attic in this old house so accessible 🙄

[@CantankerousDave]

My house is a split-level where one attic hatch is 18"x24" and is located in the entryway closet. You have to take out all of the shelves and the closet rod first if you want to get up there. And to do that, you first need to remove the heavy sliding doors.

[@barrymccaulkiner7092]

For filming simplicity and efficiency everything is pre planned. They scout out potential locations/homes. If access is difficult then filming would be, as well. These are perfect conditions, not 100% real world. Your results will vary.

[@-.__.__.-Rad]

@@barrymccaulkiner7092 I think he knew all that:)

[@b.powell3480]

It's because all these repairs/updates are pre planned and set up ahead of time, plus they know just where everything is in the walls!!, however from watching these this old house shows from day one, I did learn a lot about doing my own repairs and upgrades !, but it's a lot of dirty/dusty work!

[@Kevin-mp5of]

The job is rarely ever this accessible or clean. I installed a whole house fan last month, and between the heat and the dust I was dying up there in that attic, not to mention the rats nest of wires that I got tangled up in.

[@jaygreentree4394]

I moved out of an older duplex that has no bathroom vents. Taking a shower meant the walls would be completely wet even though the shower its self was a low flow shower head. You would have thought someone was playing in the water. My new (current) apartment has a vent in the bathroom and the difference is just crazy. I have to get the water really really hot before I even see steam on the mirror.

[@donc-m4900]

How to use old wiring, install new wiring.

[@Kevin-mp5of]

Wiring

[@donc-m4900]

@@Kevin-mp5of oops.

[@jeffwilson1399]

Dah Lobstahhs love dah new wyeahhs

[@aurvaroy6670]

Well it's better than messing with outdated wiring

[@PlayingwithPawz]

Not everyone can afford to rewire a whole house

[@louisax4058]

Oh man i was hoping to see the details of the sheet metal installation to the outside...

[@reidgleason7862]

If putting your bathroom vent directly above your shower you have to get a special fan rated for water contact due to the extreme humidity right above the shower. If not your fan wont last long at all and its a code violation where I am from.

[@krissyanne3966]

They skipped the hardest part!!! The wiring! 😂

[@feliiiik]

please make more videos focusing on older homes!

[@SomeDudeQC]

It's literally all they do lol

[@vinceromano8245]

Thought I saw a newer 12 gauge circuit (yellow wire) in the attic that appeared to power some outlets. Was that circuit not useable?

[@wizard3z868]

Correct modern code requires 20amp gfci for bath outlet only. some will let you run one circuit for all bathrooms but it has to only feed the outlet. (You can add more outlets that are 15 amp but they have to gfci/arc fault protected if with in 6 ft of water or damp location)

[@vinceromano8245]

@@wizard3z868 thanks for the update

[@steveh4098]

I like some sound in my bath fan

[@will5150]

I need more cowbell, baby!

[@amnesiac29]

agree its sort of relaxing

[@davidredpath4781]

Great Job, Heath!

[@2aminitials]

Anybody here with a fan intake in their shower notice a chilling draft while showering during the winter? I had to put an air diverter on the furnace register in my bathroom ceiling because even with the furnace blowing warm air, it still was cold when it blew towards the shower.

[@Rayfanz1]

In every rental apartment, and then my new-built home, I put old school Intermatic 60-minute mechanical timers on the bathroom exhaust fans. In my newer house, the 90cfm fans are quiet and vent well outside. Set the timer for an hour and whatever moisture or odors go directly out the roof vents. I can go to work and not leave a fan on all day or have to turn the fan off when the lights are off. I think I’ve spent $25/timer.

[@Rayfanz1]

I will add, I keep the exhaust fan on in my laundry room 24/7/365. Cat litter box is in there. Has a conventional switch.

[@matoatlantis]

6:34 That tiny tiny vertical switch misalignment (about 1-2mm off) would have bothered me.

[@adamthomas7232]

Kind of hard to tell but the new switch cover looks to be just a little smaller than the existing...

[@jaycie5021]

When you were talking about old wiring I thought you found knob and tube.

[@aurvaroy6670]

Same lol

[@aurvaroy6670]

Would've been nice if Heath showed where he tapped power from, whether its a junction box in the basement or a new circuit in the panel

[@TheDaniel688]

There was new wiring visible in the attic above the bathroom. Why run wiring up 2 floors from the basement instead of down 1 floor from the attic? Also, they make wireless switches which require no wiring and that remote motor could have tapped right into that attic wire.

[@christopherbaksh9443]

This is the best

[@spencer2365]

They must not have kids, I have an over under switch in the kids bathroom and they seem to only know how to use the one for the light. Fan never seems to get turned on as well.

[@toin9898]

They sell automatic moisture sensor switches, they're like $30, highly recommended.

[@Kevin-mp5of]

@@toin9898 if you watch the complete video he gave her that option, she wanted the timer.

[@SomeDudeQC]

​@@Kevin-mp5ofodd choice

[@natersalad889]

Haha, you sound like your union, calling a sheet metal technician for the ductwork.........

[@acerjuglans383]

His union?

[@ericjohnson8612]

Does anyone know the brand/model of the bathroom fan they install???

[@ncooty]

@4:42: What does Heath have against BX? Why would he say he wouldn't want to connect to it?

[@Kevin-mp5of]

I take it you’ve never worked on an old house, some of those old wires the insulation falls off if you just look at it wrong…

[@ncooty]

@Kevin-mp5of : Are you saying he disliked it because it was old? I thought he disliked it because it was BX. The oldest house I've fully rewired was from 1929. Is that old enough?

[@Kevin-mp5of]

@@ncooty that old insulation becomes very brittle a lot of times you just move it, and it crumbles. It’s best practice not to disturb it, and just bring in a new circuit.

[@ncooty]

@Kevin-mp5of I think you're missing my point. There's a difference between BX and old. You seem to think he disliked it because it was old, not because it was BX. It sounded to me like he just disliked BX.

[@Kevin-mp5of]

@@ncooty no, I've seen other similar segments, he disliked it because it's old and it falls apart...

[@c0mputer]

I prefer a fan with some decibels to hide the sounds after a night of Indian food.

[@HanyunGong]

how does the fan motor powered in the attic ?

[@nnamerz]

I believe the cable he ran from the basement to the attic is the power source for the fan. Then he ran another line from the motor to the bathroom switch so you can turn on/off the motor.

[@alvilla701]

I love noisy bath fan

[@What1zTyme]

Great episode, good information. Well done

[@real2rek]

Wont the outlet below the roof line blow moist air back into the attic?

[@nnamerz]

Maybe a tiny bit, but I think with the higher powered motor, most of the air gets pushed far out enough that it probably won't be a huge issue. Plus, on an older house like that, there's probably already a bunch of moist air leaking in regardless, lol

[@_kikaso]

Maybe that’s why hey put the exhaust on the gable end-so that it’s not below a soffit vent.

[@ncooty]

It's not clear where that soffit vent runs. On the gable, it's unlikely to vent back into the attic, given the orientation of the rafters, and especially since the attic appeared conditioned. That said, it might just vent the deck on the overhang, in which case that exhaust vapor might feed into a mold problem at that spot... though the vent louvers point down.

[@IAmNotAFunguy]

Well, I thought the show was going to sell her the most expensive bathroom exhaust fan with the multicolored LED light, infrared heater, and Bluetooth speaker connectivity in the same way they sold that other lady the most expensive washing machine.

[@MikeHoughtonasUnit8720]

not everyone has a fancy dandy new home

[@priceandpride]

she thinks more air will make it less cold?

[@nusermane1076]

6:29 Oh, that’s a vented roof right there … this old house told us in one episode not to vent moist bathroom air below such a roof but rather through the roof directly … is there a reason it’s ok to do it like this here? 😬

[@yarpyarp5647]

oh my.... tommy gonna be mad. And I don't get why she chose timer over humidity sensor, could have been a complete forget about it solution that you wont even have to think about that just works

[@willdahud4350]

I think it's because he emphasized how "simple" a timer is with his explanation.

[@nickbrockelman]

​​@yarpyarp5647 because sometimes you want the fan on when the shower hasn't been on. like when you're taking a dump. Using a timer instead of just a toggle switch keeps the kids from leaving it on all the time too.

[@nnamerz]

@@nickbrockelman 💯!! Was literally about to say the same thing. You wouldn't believe the percentage of customers I've dealt with that didn't even know the primary use for a exhaust fan is to vent out moisture/humid air. I'd say roughly 6 out of every 10 customers thought a bathroom fan's *ONLY* purpose was to vent out odor from farting or dropping a load, hahaha.

[@-.__.__.-Rad]

@@nnamerz mine has a humidity sensor, with override. The override is powered only when lights are 100%. The sensor can trigger it even with lights out though. When I have guests, the override is on, the dimmer set to full on. Delta BreezSmart SMT130H(10yrs and counting) - super quiet/cool for those times

[@quartzofcourse]

Idk why he said the bx is bad, it’s Miles ahead of knob and tube and rated similarly to modern wiring. A fan by itself doesn’t pull much amperage either, and with the bulbs there likely being leds now, it would only pull about as much as a single old incandescent used to.

[@xoxo2008oxox]

I got BX. My electrician said, just put a ground pigtail into the back of the box and you have a ground since the BX is grounded to the box to the panel ground.

[@minnesotasteve4479]

My first house, built in the 40's had some bx wiring. The only issue I had was the insulation inside the boxes would crumble off if you moved it too much, but the wire in the jacket was fine. Maybe he saw that and closed it back up.

[@strobelightbrian]

It does get brittle sometimes. So I do agree in certain circumstances.

[@ARClazerbeam]

BX cabling qualifies as an approved method of grounding, in my experience the insulation on the conductors can be brittle, sometimes not messing with older wiring is just the smarter thing to do.

[@Kevin-mp5of]

@@ARClazerbeam yeah, it’s best not to mess with it, nine times out of 10. There’s very little wire to work with and what little there is crumbles if you just barely touch it, you end up having to wrap everything with electrical tape it’s not worth it leave it alone, and bring in a new circuit.

[@howardpecker9536]

Wow. That's a LOT of work for a bathroom fan.

[@biffy7]

Does anyone insulate the sheet metal 4” vent? This way condensation doesn’t form in the vent pipe when the warm moist bathroom air, hits the cold attic? The condensation can lead to mold. Let me know.

[@ncooty]

The attic appears to be conditioned space given the insulation against the roof deck and the vapor barrier.

[@HenkSneev]

Much as I love TOH, these videos would be a lot more helpful if details were shown - exactly how to wire and connect to breaker, how to mount the switch to wall, exactly how to wire the motor, how to choose vent location and vent through the wall, etc. There's way too much here for a 5 minute video.

[@RedRoyce]

Well I didn't learn anything??

[@adamthomas7232]

Exhaust the hot, moist directly under the soffit vent so it can go right back into the attic...

[@zunedog31]

Actually pretty common in old homes.

[@Cravz69]

Guesses on what that would cost? I’m thinking 3K - 5K?

[@nickbrockelman]

Nooo... the remote motor fan probably cost around $100 or less. Probably $30 in ductwork and if you bought the sheet metal pieces yourself another $50 there. Wiring and switch 50 bucks with the most cost being the wiring. $230 you could easily do this job yourself, but if you were to hire a handyman and a sheet metal technician...you're looking at 2 hours for the sheet metal guy (couldn't tell you what he cost) a half day for the handyman at $50 an hour ($200) I would say about $500.00 USD should be about right ( in Missouri)

[@JoeyRiz]

Oh man… is no one gonna talk about how the plumbing vent stack is just capped off!?! Seems like bigger problems in that house are going on

[@Kevin-mp5of]

It’s not capped off, that’s a Polylok vent..

[@donl1410]

LOL, "Just that easy". Easy couple hour job. The heating guy is going to be right there. Fishing from a totally accessible basement to an accessible attic with one guy...OK. What a joke.

[@XzTS-Roostro]

So basically, y'all gave her the same solution that modern hotels utilize.

[@julieannaadade8482]

I want a bathroom upstairs

[@Kevin-mp5of]

I want a house.

[@RDC_Autosports]

you mean a “fart fan” 😁

[@johnlebzelter4208]

Wow you’re really mature. Bet your mom still makes your pop-tarts for you.

[@RandomVids519]

Ignore john hes a goof rat likes his salad tossed

[@Belg1970]

This is totally not Representative of g the effort and time it takes to install a fan like this. As a retired electrician, who calls an hvac contractor to install duct work for a bathroom fan. Don't know how old this video is but in my area we had to install all insulated ductwork to counter act the hot to cold condensation. He's a great snake guy or they cut out a ton of the time snaking to a 7/8 hole from the second floor is not that simple.⁸

[@KJEThompson]

😂😂😂

[@Kevin-mp5of]

@Navy1977 don’t mind that guy, he was dropped on his head one too many times as an infant…

[@austintrimble2985]

All that work and installs # 14 instead of # 12 lol

[@Kevin-mp5of]

It’s not necessary and harder to work with.

[@austintrimble2985]

@@Kevin-mp5of I guess it depends on your geographical location...Minimum 20a in bathrooms to pass inspection IF adopted 2023 code. But hey who am I, lol Cheers mate

[@Kevin-mp5of]

@@austintrimble2985 not required here, but needs to be on gfci breaker, except this case since it’s a remote motor location and not above shower.

[@RandomVids519]

Decent cans😅

[@jeffwilson1399]

🦞🦞🦞

[@luckybestwash]

could have saved herself a lot of trouble by installing a $25 window reversible fan

[@nachtdiertje1972]

Ever heard of a humidityswitch or even a motionsensor? More efficient and less work.

[@nathancawley6944]

He literally gave her an option for one, and she chose the timer. Watch the video before commenting.

[@Kevin-mp5of]

Ever heard of paying attention when you watch a video?

[@goldenjimbo007]

The acting is so cringe

[@Kevin-mp5of]

Nearly as bad as the copycat prolific use of the word “cringe.”

[@tacojohnhg8181]

At least 50% of the reason for the fan in a bathroom is the noise IMO. I WANT the noise. What kind of a freak wants a quiet bathroom while they're doing the deed on the toilet?

[@2loco]

Never heard of a woman with a name like that before lol.

[@jeffwilson1399]

Can't say that again now can ya?

[@TTURocketDoc]

It sounds like the name of a character from that old Killer Instincts game