Hi all. I'm looking for a quick bit of advice if possible re: bathroom fan isolators.
I need to replace two extractor fans while replacing two bathrooms. The house was built around 1990 and the fans are the originals - which are now horrible, noisy and yellowing plastic.
The existing fans are simple, on-off types which are connected to dedicated lightswitches. They run off the upstairs lighting circuit.
I would much prefer to have fans on timers or have them humidity controlled.
So, I was delighted when I removed the covers on both fans and found an unused permanent live feed - in each case this has been left in a choc-block under the fan housing. So I have everything I need to fit the fan that I would like.
However, there is not currently an isolator - instead, to work on the fans it is necessary to switch off the MCB for the upstairs lights.
The lightswitch that controls the lights has a single length of Twin and Earth (blue, brown and green/yellow) running into the loft. The supply to the fan back down from the loft is a 4-core wire with red (perm live), blue, yellow (switched live) and earth. In the loft space above the bathroom there are a number of junction boxes which are all easily accessible. The walls are dot and dab plasterboard and the wires are free to move in this space (so I could drag new cable up and down if absolutely necessary).
Here are the pics:
So, here are the questions:
I need to replace two extractor fans while replacing two bathrooms. The house was built around 1990 and the fans are the originals - which are now horrible, noisy and yellowing plastic.
The existing fans are simple, on-off types which are connected to dedicated lightswitches. They run off the upstairs lighting circuit.
I would much prefer to have fans on timers or have them humidity controlled.
So, I was delighted when I removed the covers on both fans and found an unused permanent live feed - in each case this has been left in a choc-block under the fan housing. So I have everything I need to fit the fan that I would like.
However, there is not currently an isolator - instead, to work on the fans it is necessary to switch off the MCB for the upstairs lights.
The lightswitch that controls the lights has a single length of Twin and Earth (blue, brown and green/yellow) running into the loft. The supply to the fan back down from the loft is a 4-core wire with red (perm live), blue, yellow (switched live) and earth. In the loft space above the bathroom there are a number of junction boxes which are all easily accessible. The walls are dot and dab plasterboard and the wires are free to move in this space (so I could drag new cable up and down if absolutely necessary).
Here are the pics:
So, here are the questions:
- when fitting a new fan with a timer, into an existing circuit, is it necessary to add an isolator? (the bathroom does have an opening window - which I understand changes some requirements).
- if it is necessary - then I see three places it could be fitted.
- the easiest place would be above the fan in the loft. This would simply be added in series to the final 4-core run going down to the fan. But I'm not sure if this is acceptable as you'd need to know it was there.
- The second easiest solution would be to put the isolator directly above the fan (this would be zone 3, well above the WC approx 2m from floor - as I could simply break into the plasterboard above, but don't fancy a pull switch and suspect a normal switch would be unacceptable.
- The most inconvenient thing to do would be to fit the switch on the wall outside the bathroom. This would mean bringing in an electrician as a replacement circuit would need to be run to take the perm. live from the switch location into the loft and over. It would be an incredibly easy job for them as that wall is just a stud and the cables can easily be pulled up into the loft, but I hadn't budgeted on paying someone to do this - so in this case I may have to just replace the fans like-for-like with simple on-off units.