Bathroom extractor fan smell issues

gary83

Hi,

We've been having a problem with a bathroom extractor fan for a while, to explain the layout of the house it's a ten year old three story townhouse with a downstairs toilet, middle floor main bathroom and a top floor ensuite all of which have extractor fans to get rid of humidity & smells.

The bottom and top floor works fine with no issues however when the middle floor main bathroom fan is turned on a sewer smell permeates the whole second floor, seeping into the bedrooms either side - we have no problems when the fans not turned on.

Any suggestions on how to get rid of the smell?

Crinkmeister

Do you know where all the vents are? Are they all clear? Is all the ducting free and clear?

gary83

The fans located on an external wall the vent leads directly through that outside, before posting on here I removed the fan, disassembled it cleaned the housing, blades and the ducting which looked like it hadn't been done for a long time, if at all (it's a relatively new house to us) this notably improved the suction from the fan however the smell in the next room remains if the fan turned on

Ectophile

As the fan is sucking air out from the bathroom, new air must be being sucked in from somewhere. That could be the waste down pipe.

You may need to check that the pipe is intact. Sometimes, rather than running the pipe out through the roof to vent it, they cap it with a valve at top floor level. That valve may be leaking.

gary83

Thanks I thought it must be something like that