Toilet Fan Isolator Switch how to smart?

[mrbob123]

Hi All,

Hope everyone is well!

I have a bathroom with a fan in it. The fan turns on a few seconds after you turn on the light switch and turns itself off a few minutes after the light is switched off.
I have noticed that there is an "isolator" switch located just above the bathroom door.

I have already replaced the toilet wall light switch with a smart no neutral wall switch which lets me control the light and fan.
I'd like to additionally have some kind of smart control on the fan too. So that I could turn the lights on without the fan turning on (its an en-suite and the fan is really loud ) and keep the fan on if the humidity was high.

I opened the isolator switch open and here is a pic :




I'm not entirely certain what I am looking at with the wiring. I was just looking for any advice on best way of making this smart? Presumably, a smart switch placed within the box would work , but I'm uncertain as to how the wiring would be and whether I need a no neutral one (like this https://www.amazon.co.uk/Required-Z...738551&sprefix=zigbee+switch+no,aps,83&sr=8-7) or one with a neutral like this this https://www.amazon.co.uk/Compatible...3738710&sprefix=zigbee+switch+,aps,230&sr=8-6

I also already have some of these lying around and wondering whether something like this would work at all https://sonoff.tech/product/diy-smart-switch/basiczbr3/ . I haven't really used any puck type device in the past, mostly these relays and smart wall switches so far.

Thanks in advance for your assistance, it is much appreciated!!!

 

[ProDave]

Don't over think it.

Fit a perfectly normal 2 gang light switch just outside the door, one switch for the light, one switch for the fan. If you go for a pee in the night you don't need to turn the fan on.

 

[Sharpend]

Don't over think it.

Fit a perfectly normal 2 gang light switch just outside the door, one switch for the light, one switch for the fan. If you go for a pee in the night you don't need to turn the fan on.

Ah yes but that doesn’t incorporate the all new singing and dancing ‘Smart’ switch! Who really needs a smart switch for a bathroom anyway?
I do think that people come to rely upon technology far too much these days, how difficult is it to push the switch one way or the other???? What will they all do in a few years time when the internet fails?

 

[mrbob123]

Thanks for your posts.

I presume you mean I could replace the isolator switch with a 2 gang switch? The isolator switch pictured above is located above the bathroom door frame, so not really an easily accessible place.

The toilet light switch outside just has one cable running to it with the red , black and earth. I'm not sure I'd be able to put a 2 gang switch there without running extra wiring within the wall and not sure something I could DIY?

Being able to turn the light on without the fan on is exactly what I'm after as you've described. It's very annoying and not needed all the time and a waste of electricity too.

Playing with automation and tech is a hobby, no need to patronise, I was just asking for some advice. I was going to automate the fan based on humidity in the toilet. It would all be local so no internet needed.

Any further pointers/tips? How can I seperate the fan from the lights? As the isolator switch is above the door frame then surely this would then be a decent use case of a smart switch maybe? Better use case than the toilet lights granted!

 

[Sharpend]

When you go to bed switch OFF the switch above the door this will stop the fan from running altogether, when you wake up switch ON the switch above the door and this will bring the fan back online.
If you want to control the humidity then swap fan for a humidity controlled fan, it will probably be quieter as well as new.
All solved without the use of anything smart other than a brain?!
I don’t mean to be patronising, I just think that we are driven to overthink the simplicity and technology is thrust upon us for the simplest of tasks.

 

[mrbob123]

Completely agree with your comments at the end there Sharpend!
I see tech slightly philosophically, as anything digital or not that makes our life better. Often the simplest stuff is best , "tech" that just works! It was not my intention to thrust anything in your face. This is part of my own exploration of technology and what it can and can't do and whether it does actually improve our lives or not.

So far I've learnt very little stuff commercially available is actually smart and would actually improve your quality of life!


I'm not an electrician but have been toying with these smart switches for a while , hence my thoughts were from this perspective. I just ultimately want to solve the problem! And I thought that by posting here I might also better understand the wiring and how it works in the process.

When you go to bed switch OFF the switch above the door this will stop the fan from running altogether, when you wake up switch ON the switch above the door and this will bring the fan back online.
If you want to control the humidity then swap fan for a humidity controlled fan, it will probably be quieter as well as new.
All solved without the use of anything smart other than a brain?!
I don’t mean to be patronising, I just think that we are driven to overthink the simplicity and technology is thrust upon us for the simplest of tasks.

Unfortunately we are both relatively short and need a ladder to get to the isolation switch which makes it extremely inconvenient to do every night.
I'll look into humidity controlled fans , thanks I wasn't aware that these existed!

I've been using home assistant for the last 3 years , so already have all the setup and switches etc. I'm also a fan of cost effectiveness and if a £5 switch word save me from buying a £70 humidity controlled fan then I'd go the first way!

How do I figure out which wires the fan connects to? I'm presuming the switch switches between fan connected and just lights connected. If I was to replace with a 2 gang , where would the existing wires go onto the 2 gang switch?

 

[ProDave]

I am used to sensibly built houses with timber stud and plasterboard walls where it is relatively easy to pull an extra cable between the isolator and light switch box for the second switch. If you have the misfortune of being in a brick house with "plaster on the hard" then it is a much bigger and disruptive job. Glad i don't have to do that very often.

So as above, regard the fan isolator as off (silent) at night and on at all other times.

EDIT: Looking at your pictures again, that is a dry lining box so a plasterboard wall. Get a local electrician to have a look, it should not be too hard to pull an extra cable in, or use the existing switch drop cable to pull a 3 core & earth in it's place to allow 2 switches one for fan one for light. Get someone to have a look and give you a quote.

 

[Sharpend]

Do your lights work when that switch above the door is ‘Off’ ? I’m curious as to why there are two reds in one terminal and two blacks in the other, it could be that the. Line and neutral have been ‘looped’ through the isolator I guess. What cables have you at the switch and light?

 

[mrbob123]

Thanks all for the tips! That's helpful to know about the wiring and setup with the wall. If I don't get very far with switches then I'll look into it! Especially helpful incase if comes in handy for elsewhere too , thanks!

Can confirm that the isolator switch just turns the fan off.

Attached a pic of the inside of the light switch (from before I replaced it , not the best picture apologies).

What do you think? How would you say convert that into a two way switch for example?

 

[ProDave]

Thanks all for the tips! That's helpful to know about the wiring and setup with the wall. If I don't get very far with switches then I'll look into it! Especially helpful incase if comes in handy for elsewhere too , thanks!

Can confirm that the isolator switch just turns the fan off.

Attached a pic of the inside of the light switch (from before I replaced it , not the best picture apologies).

What do you think? How would you say convert that into a two way switch for example?

You will either need to get an additional cable between the light switch and the isolator switch, or replace the existing cable with a 3 core and earth, that might be easiest using the existing cable as the draw wire to pull the new one through.

This is a slightly unusual wiring configuration in that all the wiring is looped at the isolator switch, so not really a job for someone that knows nothing about electrics but a competent electrician could do it for you. The crux of the job is whether you can indeed pull a new cable through without making too much of a mess of the wall. If you can for an electrician it is an easy job.

Could you post a picture of the wall showing both the light switch and the isolator switch and where they are on the wall in relation to each other?

 

[Fleeting]

The existing fan switch is an isolator so if it is removed and replaced with an alternative accessory such as a light switch then you have lost your isolator, a light switch is a functional switch and not an isolator. Unless I am misreading what you intend to do.

 

[ProDave]

The existing fan switch is an isolator so if it is removed and replaced with an alternative accessory such as a light switch then you have lost your isolator, a light switch is a functional switch and not an isolator. Unless I am misreading what you intend to do.

He wants to control the fan separately so my suggestion is an extra cable to enable a 2 gang switch in place of the single gang switch and the fan isolator would remain.

After years of asking nobody has actually shown me the reg that says we must have a fan isolator switch. I don't fit them unless the customer asks, BC have never had an issue with that, and I recommend removing them in rental properties so the tenant can't disable the fan and then complain about condensation and mould.

 

[mrbob123]

Thanks for your comments , they are really helpful and appreciated!!

Here's a pic of the two switches.
Definetely reckon you are right pro Dave , wall sounds pretty hollow when you tap it.

Shame it's not really DIY able !
I do have a bit of experience with general electronics , low voltage stuff but not a huge amount of experience with electrics!

Surely I could pull some wires out of the isolator switch and hook in a relay or switch at the isolator box to control the fan? I'm surprised that it's not simpler ! Is that because this wiring is slightly unusual as you mentioned?
Feels potentially like a lot simpler than getting someone to put a wire through the wall?
But very grateful for your advice, looking that I will have to call an electrician in the end!

 

[monkey5]

https://www.toolstation.com/1-chann...fpzFZ-D_wsPAvj89u4MaAuOQEALw_wcB&gclsrc=aw.dsWhat about some thing like this with the appropriate switch. Might need to install deeper fan isolator back box or an additional one next to the other one with a blank on it.

 

[Sharpend]

Is this an upstairs bathroom? If so pop your head through the loft and trace the bathroom cables to switch and isolator. If the wall is hollow then fishing a cable is relatively straightforward.

 

[ProDave]

Is this an upstairs bathroom? If so pop your head through the loft and trace the bathroom cables to switch and isolator. If the wall is hollow then fishing a cable is relatively straightforward.

Yes i would expect all the cables from the fan isolator switch to go straight up into the loft and likewise the single cable from the switch, so you should be able to fish a second 1mm twin & earth from the fan isolator box up into the loft, across to where the switch is and down to the switch.

 

[Murdoch]

I really don’t see why anybody would want a smart switch to control their extractor fan ….. odd move imho

 

[mrbob123]

Good thinking but it's a flat in one of those old converted warehouses , think it was done around 2003-ish.

https://www.toolstation.com/1-chann...fpzFZ-D_wsPAvj89u4MaAuOQEALw_wcB&gclsrc=aw.dsWhat about some thing like this with the appropriate switch. Might need to install deeper fan isolator back box or an additional one next to the other one with a blank on it.

This looks intriguing! Didn't know these existed! This would actually fit the bill perfectly. How would I wire the extra switch in?

Love how funny you guys find this. Understandably I guess too in some ways ah. But it's now somehow looking like the "smart" option might actually be the cheapest way to go (although granted I've got all the other stuff already).

 

[Geoff1946]

Simpler and cheaper still, I find that a small battery operated PIR sensor led light is more than adequate for night-time excursions into the bathroom. Goes with me to hotels and in our caravan too.

 

[brummydave]

Good thinking but it's a flat in one of those old converted warehouses , think it was done around 2003-ish.

This looks intriguing! Didn't know these existed! This would actually fit the bill perfectly. How would I wire the extra switch in?

Love how funny you guys find this. Understandably I guess too in some ways ah. But it's now somehow looking like the "smart" option might actually be the cheapest way to go (although granted I've got all the other stuff already).

The switches for this system aren't wired in. They are battery powered, the battery charged with kinetic energy every time the switch is operated. (Hence the name).
They're genius and can work out cheaper than a wired system due to labour saving!
You can have up to ten switches for one receiver, that can have a wi-fi option if you want.
In your case you'd put the receiver either next to the fan in a ceiling void or next to the isolator.

They do grid switches as well so it's possible to have a normal switch and quinetic switch next to each other without telling which is which!