Our 23 year old bathroom exhaust fan works fine (lubricated, cleaned and shimmed to keep it quiet). Once we put the cover back on we noticed that the air blows INTO the bathroom - shouldn't it be sucked OUT? If this is indeed a problem, any suggestions on repairing the air blowing into instead of out of the bathroom?

Most such fans have a small switch somewhere on them that controls whether they blow in or out. Possibly that got bumped accidentally when you removed or replaced the cover.

But a 23-year-old one may not have such a switch. Are you sure it hasn't always been blowing air in instead of out?

Thank you for your reply. I will check for the switch you mention - we never noticed this problem before since the fan was so noisy and (seemingly) inefficient. It wasn't until I brought a new one home that my husband decided to take a closer look at the old one ;-).. It's possible that the vent pipe is also clogged with something or the flap is rusted shut. All of these are suggestions we will look into tonight.

I have never seen a bathroom exhaust fan with a selector switch, and I will gamble and say none exist, exhaust fans draw the air out of the room, if the air is not being drawn out, the duct is probly blocked and the air is backing back into the room. check the flap on the fan to see if it move freely, ducts get broken and damaged if people step on them in the attic also.