On Wednesday, January 29, 2020 at 8:57:39 PM UTC-5, micky wrote:
Do electric roof fans rust enough that they must be replaced?

My fan, in the pitched part of the roof, looks like new from the inside.
The plastic top, the metal screen**, and the metal frame below the
screen. all look perfect.

**Not wire screening but sheet metal with a lot of holes in it.

But the roofer who came yesterday wants to replace it, because he says,
it's rusting.

He also says the new one will be better, new thermostat, new humidistat.

My current thermostat works fine, I never take steamy showers or baths
so I don't need a humidistat.

I'm a little curious. Do steamy showers or baths affect the humidity
in the attic space that much? My bathroom vent fan exhausts to the
outdoors, so I've never thought about the humidity that might leak
around the fan housing. (The attic access--right outside the bathroom--
has a gasket.)

Cindy Hamilton