Bathroom Soffit Vent Flap Freezing

[velvetfoot]

The flap on the end of the bathroom soffit vent is freezing shut.
I've had to open it up with a stick for the last couple of days.
I'm thinking about adding a switch timer to run the fan for a while after turning it on.
The vent I have is this: (broken link removed to http://www.hardwareandtools.com/invt/9261165)

Any other ideas?

 

[mayhem]

I think you're on the right track with the timer...odds are its still got moist air flowing when you shut it down and that moisture is freezing it shut. Me, I'd just leave it running and walk back in the room 10 minutes later.

 

[velvetfoot]

I could try that too, but it's not just me, plus leaving for work in the AM, probably wouldn't run long enough, stairs, etc.
The downside is that the fan gets turned on just about all the time by people going in there, so it'll be running too much.

 

[fbelec]

i can see if it was sticking after a shower but if it is doing the same thing everytime then i would get up there and put some vasilene around the edges that are sticking. not a thick glob just put it on and wipe it off with your finger to leaving a trace. i had the same thing happen to the inner flap at the fan when i moved in. the lady that owned the house was a smoker. the flapper got sticky from the smoke. took it out cleaned it and now works fine.

 

[mayhem]

For awhile I had a motion sensor in my downstairs bahroom for the lights and it had an adjustable runtime. Set it to 15 minutes after motion stops and you'll be good. Its really cool when the lighs just come on when you walk into the room. She hated it so I took it out.

 

[velvetfoot]

That's a good idea.
Maybe some of that plumbers silicone grease, which wouldn't have petroleum.

 

[daveswoodhauler]

Funny, I am having the same issue, but mine is sticking open (I have the same one too)

You could probably take the little flap off, and just shave down a minute portion of the plastic around all the sides and top/bottom of the flap. This would present a little more of an air gap between the flapper and the vent housing, but it might stop it from sticking. (The grease might be a good idea too)

 

[velvetfoot]

I guess that's why they were cheap.

It's the ice in my case that's making it stick.
Did you keep the flapper in the fan, and does create too much back pressure when the outside flapper does work?

 

[daveswoodhauler]

I guess that's why they were cheap.

It's the ice in my case that's making it stick.
Did you keep the flapper in the fan, and does create too much back pressure when the outside flapper does work?

Yeah, you live and learn

Mine only sticks from time to time....when it is really windy out.....I actually don't think mine is getting frozen, it just seems to sometimes take 3-5 minutes of so before closing sometimes....still works pretty good I think fr the $4 spent

 

[gzecc]

Don't use the fan in the cold winter months. You probably need the humidity in the living areas anyway. Leave the door ajar when showering and leave the light on, to slow mold growth.

 

[fbelec]

i have also seen the vent on roofs warp ever so slightly to start that pain in the rump. if you were to put vasilene on it the water should not stick to it to make it freeze shut.

 

[Highbeam]

My roof vented fan outlet is sticking shut too. When it gets really cold it will freeze overnight. Since there is a bug screen I can't get vaseline on it so I shot it with some wd-40 which didn't work. It only happens when weather is down in the low teens so not often enough to worry about it. I hate not having a proper fan working and I love dry winter air. In my case the cold outside air just freezes it shut with frost.

 

[velvetfoot]

Wandering around on the roof in winter is one disadvantage of a roof vent.

 

[fbelec]

wd40 is a water displacer. if you notice a few days after spraying it, it's gone. you don't want something to thick if you can't touch it. try using silicone spray. the stuff is super thin and slippery.

 

[velvetfoot]

I'll check things out more tomorrow.
It's stuck every time I look.
There might be a slug of ice at the outlet...have to check it out.

 

[Highbeam]

Wandering around on the roof in winter is one disadvantage of a roof vent.

You got that right. I was scared as heck of sliding off of the frosted roof. I have some silicon spray lube that I use for weatherstripping, maybe I'll try that next.

 

[velvetfoot]

I left the fan on for an hour or so last night and this morning it worked.
It still seems to have to run for a few seconds to build up pressure to overcome the flap pressure. Seems to.
Tonight I'll see if I can reach up there and clear out any ice that might be there and put something or other on the edge.
I'm thinking something greasy, even if plumbers silicone grease, might not be the ticket.

 

[mayhem]

Just look around for a good low temp grease so you don't wind up with enough water in it to freeze all over again.

 

[velvetfoot]

I'm thinking just a film of 'whatever' grease on the edge where the flap seals.

 

[mayhem]

Ought to work...so long as it displaces water and remains fluid in the temps you get in there it shoudl be fine.

 

[velvetfoot]

There could be a big slug of ice in there.
I'll find out tonight.

 

[mayhem]

Hair dryer on high for a few minutes ought to fix that right up!

 

[velvetfoot]

It was working okay again when I got home.
No big slug of ice in there or anything.
I put a thin layer of plumbers silicone grease on the edge.
The 100% silicone grease was still quite thin even after being in the cold garage, and it is very slippery.

Lesson for me: If flap sticking, open flap with stick and run fan for a while to melt ice.