Brown liquid from extractor fan, unable to insulate duct - help!

25 Apr 2022
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United Kingdom
As winter months have hit, our extractor fan has begun splurting out brown liquid. We have put this down to condensation. Unfortunately the duct runs up through the loft, and our loft space is fully insulated with no walking space, so we're not really able to insulate it. Also, it goes up INCREDIBLY high so even if we could get to it, we'd only be able to insulate about 20% of it.

Should note we also cannot access the roof to check the outside of the duct, due to the slope of the property.

Does anyone have any suggestions on how to prevent this? We're having to re-paint our freshly renovated bathroom :(
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Sounds like the sh it really has hit the fan here :)

If you cannot access it then your kinda stuffed, can you open the front of the fan and look inside?
That may point you towards the problem.
Perhaps there is a screw used somewhere along the duct thats rusted?

If it's running down the duct then your only option would be to either look at the exit or get to the duct in the loft area to check it out.

If its only a little dribble and after looking in the fan you have determined that it is coming from the ducting and your absolutely unable to go any further then perhaps fix a small sponge in there to absorb the liquid as it comes down - this may need occasional cleaning.
Post some photos please.

How long do you run the fan for, before and after your shower?

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