Bathroom extractor fan supply

[robinsoncrusoe55]

Need some advice, regarding the wiring of an extractor fan in a bathroom.....can it be supplied from the nearby immersion heater circuit, using a switched fused spur unit, as the nearest point of supply, is from a ring main socket, on the other side of the wall, which is already fed from below with 2 runs of conduit, into a single backbox.
does the extractor fan isolator switch, need to be outside the bathroom, or can it be inside, in the zero zone..... ie positioned close to the fan approx 100mm down from the ceiling level. Many thanks

 

[Taylortwocities]

The immersion heater circuit should be dedicated to the immersion heater.

The fan is usually powered from the lighting circuit.

The isolator is usually outside the bathroom. It can go outside zones 0,1 and 2 but the switch must be suitable for the damp steamy environment of a bathroom.

Don't forget that the circuit for the fan will have to be RCD protected, and this is notifiable work. See the WIKI re Building Regulations Part P.

 

[ban-all-sheds]

does the extractor fan isolator switch, need to be outside the bathroom, or can it be inside, in the zero zone

I would advise strongly against putting a fan isolator in Zone 0.

The immersion heater circuit should be dedicated to the immersion heater.

Not a major issue if it's not, though.

But I agree - the lighting circuit is the usual choice.

 

[robinsoncrusoe55]

Sorry.... I think i've confused myself!!....... what I meant to ask was, can the extractor fan isolator be installed in zone 3, which is close to the fan ( and above it).....on the opposite side, to where the bath is fitted. I can't run off the lighting circuit, as we are in a flat, (ground floor)...... and all the wiring is run in metallic conduit, and i'm a bit concerned about cutting into the ceiling material...... not fully knowing its "make up".
If i do extend the metallic conduit, from the kitchen single socket..... is it acceptable/legal, to run horizontally 4 feet, and then vertically, approx 3 feet, to reach the desired position, and then to fit a switched fused spur?..... phew!!!, my brains hurting me now!![/b]