Why doesn’t my bathroom vent work?
Geeze, I don’t know. That’s a little like calling a mechanic and asking “How much will it cost to fix my car?”
But I can say for certain what the most common problem is; stuck or blocked vents. Roof vents for bathrooms have doors (called “dampers”) on them that keep cold air from coming back into the house. They also have screens, which help keep birds from building nests.
Sometimes, the heat of the sun melts a gasket on the damper. When the vent cools down, the gasket gets sticky, and stays shut. If that’s the case, you can contact the company that makes them, or simply have the gasket removed or replaced. When I find them stuck shut, I force them open with a screwdriver. But I know the problem will come right back.
You should replace broken vents (or vents with broken dampers) right away. I can tell you, it’s very hard to get bird’s nests out of vents! And when the damper stays open, cold air gets in too, which causes even more problems.
If it’s a vent that is supposed to let air in, it should have a screen. Not a screen used for windows; that’s too fine. Use hardware cloth of 1/4″ to 1/2″. Be sure to keep the screen clean. It fills up with lint quickly, especially when the vent is near the air conditioner unit.
And look out for wasps. They LOVE those little hoods!