Fans/ducting problem - what kind of tradesperson do I need?

Jennifer83

I'm having a number of issues with extractor fans in my flat which I *think* are all connected. Not sure if I need an electrician or some other kind of expert though and wondered if anyone could advise?

I live in a purpose built flat which has a toilet and bathroom in separate rooms, neither of which have external windows. The survey I had before purchasing the flat said the fans in both these room are ducted through the kitchen – I assume because of the layout where bathroom/toilet walls are internal to the flat or block so there's no other means of escape!

Current problems. 1: In the bathroom, there’s a humidistat Airflow fan which has become very temperamental (after working mainly fine for just over a year since I moved in). E.g. it now sometimes turns on if am cooking in the kitchen and stays on for ages, but then won't always turn on when the shower in the bathroom itself is being used.

2. No one (including survey I had done) can work out what is supposed to activate the fan in the toilet (it's not the light and there's no other switch) so has never really worked since I've lived here. This looks like an older style fan with a separate ball thing that has plus/minus dials for Time and Lux. This fan also occasionally comes on when the kitchen extractor fan (cooker hood) is in use and/or when the bathroom fan is on.

Obviously an electrician will need to be involved at some stage but I don't know if I need someone else as well as seems like the ducting/sensor situation is a bit confused?! I tried having a look for electricians that would specialise in this but don't think I'm using the right terminology! Would massively appreciate any advice. Thank you

Fire_Fox

"BPEC Domestic Ventilation Installer": an extra qualification several trades can do (inc. electricians and plumbers IIRC).

How long is the ductwork/ how many right angle turns?

coffeehound

The ball thing sounds like an occupancy sensor to trigger the fan when someone is in the room.

Jennifer83

Thank you both - that is very helpful.

Fire Fox - duct work is just under 4 metres, two right angle turns close together between toilet and kitchen and (I think) one more turn far side of kitchen to take it outside.

Will have a look for a BPEC Domestic Ventilation Installer.

And consider whether I am a ghost occupant...

Fire_Fox

Try downloading user manuals for the kitchen cooker hood and bathroom fan, follow all maintenance or troubleshooting activities. For example vacuum out to remove dust and cobwebs/ clean or replace grease filters.

You should also be able to establish if your model bathroom fan is the 'right type' for a moderate duct run with several bends (mess with air flow). Or if it may be reaching the end of its expected life. A like-for-like replacement shouldn't be wildly expensive if you don't need to mess with the ductwork.

Don't think the kitchen and bathroom ductwork should be connected, because that would be a fire risk. Can run alongside one another in the ceiling void though and the ducting might be damaged, say if plastic flexipipe. BPEC person can test it anyway. Are there two exit points (plastic louvred vents) on the outside wall, even if adjacent to one another?

Maybe poor performance in one (?kitchen) is affecting the humidity within the flat itself, messing with the normal function the the others (?bathroom and toilet).

You deserve :T for being so clued up from the outset. Hope it is a fairly easy fix.

ComicGeek

Always worth having a fan with trickle and boost modes, if you're replacing them. Helps to provide some constant background ventilation, rather than waiting for the bathroom to become too humid before operating.

coffeehound

coffeehound wrote: »

The ball thing sounds like an occupancy sensor to trigger the fan when someone is in the room.

If I've got it right in my head, the lux dial should be set to maximum so that it works in any light level.

The timer one sets how long the fan stays on once it's been triggered. Suggest setting it just a bit above minimum to test whether it works.

Jennifer83

ComicGeek wrote: »

Always worth having a fan with trickle and boost modes, if you're replacing them. Helps to provide some constant background ventilation, rather than waiting for the bathroom to become too humid before operating.

Thank you! I knew zero about what I should be aiming for - that's helpful

Jennifer83

Fire_Fox wrote: »

Try downloading user manuals for the kitchen cooker hood and bathroom fan, follow all maintenance or troubleshooting activities. For example vacuum out to remove dust and cobwebs/ clean or replace grease filters.

You should also be able to establish if your model bathroom fan is the 'right type' for a moderate duct run with several bends (mess with air flow). Or if it may be reaching the end of its expected life. A like-for-like replacement shouldn't be wildly expensive if you don't need to mess with the ductwork.

Don't think the kitchen and bathroom ductwork should be connected, because that would be a fire risk. Can run alongside one another in the ceiling void though and the ducting might be damaged, say if plastic flexipipe. BPEC person can test it anyway. Are there two exit points (plastic louvred vents) on the outside wall, even if adjacent to one another?

Maybe poor performance in one (?kitchen) is affecting the humidity within the flat itself, messing with the normal function the the others (?bathroom and toilet).

You deserve :T for being so clued up from the outset. Hope it is a fairly easy fix.

This is SO helpful, really appreciate the response and clear explanations! Would make sense that cleaning out is needed/at least one element needing to retire as I've done no maintenance on any of it since moving in 18 months ago and imagine there wasn't a lot done before that!

Good to know about how the ductwork should be...I tried to see about the exit points but need to wait till it's light! (I'm on top floor and can only see a few lower floors which don't all seem to be the same...)

Anyway, you have helped loads and I'm definitely in a better position to get someone in if first step doesn't work. Don't think I deserve :T .... clearly asked in the right place! Thank you v much

Jennifer83

coffeehound wrote: »

If I've got it right in my head, the lux dial should be set to maximum so that it works in any light level.

The timer one sets how long the fan stays on once it's been triggered. Suggest setting it just a bit above minimum to test whether it works.

Ah that makes sense - thank you. Funnily enough the Lux dial seems stuck at lowest setting (I can turn the timer one) so may be part of the problem! Will see if can have more of a fiddle. Thank you!