Bathroom Extractor Fan Switches

[adzyp]

Hi All,

Currently got a timer ceiling extractor fan in the bathroom. It has its own isolator switch above the door which is always set to on and then its also hooked up to a 4 gang switch next to the door (rest are different lights) - before we had the bathroom done a couple of years back it was only ever controlled by the isolator switch so no sure why this extra switch was added?

When we have a shower we hit the switch on the 4 gang by the door, the fan kicks in and then after the shower we turn the 4 gang switch back off and the fan eventually turns itself off after the set amount of time.

Now im going to install one of the humidity sensor ones so that it switches on/off based on humidity levels, therefore I want it on all the time and would like to revert back to just using the isolator switch therefore disconnecting the other switch on the 4 gang panel.

Im not bothered about swapping the 4 gang for a 3 gang if it means having to fit a smaller 3 gang switch half the size and then filling in a hole (unless the do a 3 gang the same size as a 4?), so im happy to just disconnect it and have a dumb switch, but where will it be connected to at the other end?

Im guessing that if it was only ever operated by the isolator switch in the past I just need to disconnect this extra connection?

 

[RandomGrinch]

Just connect the two wires on the switch in the '4 gang' into only one of the terminals - simples!
...but that may leave the fan running non-stop!

By the sound of your current set-up - your existing fan has a switched and permanent live - allowing for the run-on delay.

Basically, you don't need to change anything in your setup.

Your new fan should run perfectly, coming on when the humidity is high - without the need for the switch to be pressed.

Keeping the switch, will allow you to turn on the fan manually, even if the humidity isn't high.

I hope that makes sense!

 

[adzyp]

Just connect the two wires on the switch in the '4 gang' into only one of the terminals - simples!

But will the fan still get the power? Im under the impression that the fan needs to have that switch turned on for it to work in its current setup? I want to remove both ends of that connection completely so the only on/off is the isolator

 

[RandomGrinch]

But will the fan still get the power? Im under the impression that the fan needs to have that switch turned on for it to work in its current setup? I want to remove both ends of that connection completely so the only on/off is the isolator

Sorry, try a refresh! I was still typing when I pressed the post button!
As your existing fan 'runs on', after the switch is turned off, it means it already has a permanent live attached.
Your new fan will utilise this permanent live to come on with increased humidity, whether the switch is pressed or not!

 

[adzyp]

Sorry, try a refresh! I was still typing when I pressed the post button!
As your existing fan 'runs on', after the switch is turned off, it means it already has a permanent live attached.
Your new fan will utilise this permanent live to come on with increased humidity, whether the switch is pressed or not!

Ok, I get you. I'll just have to give it a try then once I install the new one.

Just out of interest though, should I ever want to remove the switched live from the 4 gang, I assume the other end is terminated somewhere on the fan itself (same for the isolator switch)

 

[RandomGrinch]

Ok, I get you. I'll just have to give it a try then once I install the new one.

Just out of interest though, should I ever want to remove the switched live from the 4 gang, I assume the other end is terminated somewhere on the fan itself (same for the isolator switch)

The switched live would pass through the isolator, and onto the the SL connection on the fan.
Finding where the live to the switch comes from might be the issue.

If you are interested, a search for '3 gang switch double plate' should bring up some suitable light switches.

Although personally, I would keep the switch as it is - you never know when you may need a 'boost' of ventilation!
...and if the fan isn't quite in the right location, the humidity may build up too much, before the fan operates.
...or it all works perfectly and you can remove the switch! Have fun experimenting!