bathroom extractor to loft leaking

worlestone

I'm looking for some help in how to resolve an ongoing problem we have with a bathroom extractor fan in the loft.

Fitted 18 months ago, we had to call the electrician back due to water (condensation) coming through the ceiling as flexible pipe had been used which filled with condensation.  The electrician refitted with rigid pipe, a short straight up from bathroom, then a 90 degree angle, short run to extractor vent and a longer pipe to a soffit vent, with a downhill run from the bend to the soffit vent.

It seems the fan has packed up and there's water leaking again from the extractor fan onto the rafters and ceiling.

I'm thinking the fan should really be on the vertical pipe with a condensation trap followed by the bend and run to the soffit vent... is that right?

Photo attached...

ic

The ducting should be insulated and as short as possible.  When flexible is used it should be pulled reasonably tight to remove excessive twists and turns.  https://www.screwfix.com/p/manrose-aluminium-insulated-flexible-ducting-hose-silver-10m-x-102mm/90765

I imagine you could probably get away with wrapping the pipework in loft insulation (not the fan - you don't want it overheating!).

Does the fan have a sufficiently long overrun / humidistat, so that it keeps running until the room is clear of damp air?

tacpot12

The vertical duct could also be fitted with a condensation trap like this one: Condensation Trap 100-110mm with Overflow Connection

This will allow the condensation to be drained outside of your home rather than falling back into the bathroom. 

Whether or not the duct should have been fitted with one of these from the outset is debatable. 

 

Lorian

That doesn't look like too bad a job - you will almost certainly fix the issue by emptying the pipe (and replacing the fan if its dead) and wrapping it or covering it with 100mm loft insulation. The requirement is just to keep the air hot until it exists through the soffit vent - so it condenses outside and not in the pipe. might want to fit a backdraft shutter in the pipe if it doesnt have one.

worlestone

Thank you for the comments, so replace fan and insulate.  There's no condensation dripping back to the bathroom, just the broken fan and water leaking from this, it was making a 'clicking' noise on a very cold day, so maybe it was ice.

greyteam1959

Has the fan actually packed up ?
Or is it frozen up ??
If it is making a clicking noise it may be trying to work ?
Why don't try putting a fan heater near it for an hour or two ?

worlestone

greyteam1959 said:

Has the fan actually packed up ?
Or is it frozen up ??
If it is making a clicking noise it may be trying to work ?
Why don't try putting a fan heater near it for an hour or two ?

The fan had frozen up, it turned out to be ice causing the clicking noise.  I guess the solution then is to drain and insulate some how

Chickereeeee

I actually used some of the insulation from flexible ducting pulled over the rigid ducting. Seemed to work OK. Has to be the right size, of course.