It should open only under pressure from the warm air to let it out and remain closed the rest of the time.
Bathroom exhaust fan leaking water.
If bath fan ducting isn t properly insulated the moist air from your house will condense inside the duct.
The bathroom exhaust fan is terminating in the attic.
The first step is to head to the attic.
You can expect water to come out of the shower or the faucet.
If water drips from the bathroom exhaust fan the damper that normally controls the flow of air through the pipe may not be working correctly.
However you shouldn t expect for it to come out of your leaking bathroom exhaust fan or ceiling vent.
Water stains on the ceiling around your bath fan may indicate a leak coming from the vent cap on your roof but condensation is the more likely culprit.
After all this is where you take a bath.
You can expect your bathroom to get wet.
You may think there is something wrong with the exhaust fan but this is not always true.
When it does then there s obviously something wrong.
The fan pulls warm moist air from the bathroom and distributes the air to the attic.
On a cold day the moisture in the air will condense on anything below the dew point.
To find the problem and fix it you must keep your head cool.
There may be damaged insulation damaged drywall damaged wood framing and there may be mold growing.
If your leaking bathroom exhaust fan has been going on for some time it may be a very good idea to remove the actual bathroom exhaust fan and check for damage in the ceiling cavity.