Is your bathroom ceiling flat? I have two fans mounted in vaulted ceilings. The factory fan damper is only intended for flat/level mounting as it is just a gravity close. I fixed mine by carefully flexing the discharge pipe housing slightly to remove the flapper (don't break off one of the plastic pin axles). This is done from the ROOM side of the fan housing, so need to get in the attic. Then drilled a 1/4" hole right in the center of the plastic flapper. Install a 1/4x20 screw through the hole with a nut on the back side and then a counter-balancing pair of nuts jammed together out at the end of the screw or however far out you need to get the flapper to just gravity-balance plus maybe one turn for good closure. I think mine only took about a 1" long screw.
Works perfect. I tested mine by running the fan and it EASILY still blew the flapper wide open and my vaults are about 40deg. With an even shorter screw, and maybe only one (or no) nut, would probably add just a bit of extra gravity-closure for even a flat ceiling fan.
Forgot to add - my fan discharge pipes were only 3", which I think is standard. I saw the 4" backdraft dampers, but found that 3" backdraft dampers were either unobtainium or stupid expensive or both, as were 3" to 4" adapters.
- Jay
Works perfect. I tested mine by running the fan and it EASILY still blew the flapper wide open and my vaults are about 40deg. With an even shorter screw, and maybe only one (or no) nut, would probably add just a bit of extra gravity-closure for even a flat ceiling fan.
Forgot to add - my fan discharge pipes were only 3", which I think is standard. I saw the 4" backdraft dampers, but found that 3" backdraft dampers were either unobtainium or stupid expensive or both, as were 3" to 4" adapters.
- Jay
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