Bathroom Extractor Fan Dilemma

[Brentb]

My bathroom extractor fan was not turning itself off, remaining on permanently. I subsequently bought a new one imagining the original to be faulty. Intending to replce it I discovered the live, switch live and neutral wires - by also an addition two wires (earth or something?). It also dawned on me that probably it was the wiring of the original fan that was faulty and not the fan itself. How do I now attach the new fan - ie what are the other wires for, and how do I rectify the original wiring fault?

 

[ban-all-sheds]

What do the instructions that came with the fan say you should do?

 

[Brentb]

What do the instructions that came with the fan say you should do?

They provide instructions for the neutral, live and live switch but not the other wires, they obviously do not recommend any course of action for a fan that runs all the time, regardless of the light being on or off.

 

[breezer]

may be the timer on the fan is faulty it is quite common.

 

[Brentb]

may be the timer on the fan is faulty it is quite common.

Thanks, I'll check that, but the odd thing is it works better if it's loose a bit. When it's tight to the ceiling - as is should be, it runs without stopping.

 

[ban-all-sheds]

Well that doesn't sound right, does it?

Given that you've got a replacement, you might as well replace it.

I take it you can identify the Live, Switched Live and Neutral wires OK?

I'm not sure what "I discovered the live, switch live and neutral wires - by also an addition two wires (earth or something?)" means - does the existing fan have 5 connections? Which ones are always live, which ones are only live when the light is on, and which are neutral?

 

[Brentb]

Well that doesn't sound right, does it?

Given that you've got a replacement, you might as well replace it.

I take it you can identify the Live, Switched Live and Neutral wires OK?

I'm not sure what "I discovered the live, switch live and neutral wires - by also an addition two wires (earth or something?)" means - does the existing fan have 5 connections? Which ones are always live, which ones are only live when the light is on, and which are neutral?

Yes, live, switched live and neutral I've identified there is also an earth and another wire (can't remember the colour but will check. I think you're right, I'll fit the new one and see if it solves the running problem. what is the correct proceedure with the earth? I might just have to get qualified help on this and work my way up slowly from fitting plugs or something....

 

[ban-all-sheds]

If the fan has an earth, it should be connected. If it hasn't (i.e. it's double insulated, then there will be nowhere to connect it anyway, so just cut it off tidily and make sure the end won't poke anything it shouldn't.

Don't forget that if there is an earth it will also need to be connected to the supplementary bonding in the bathroom.

As for the other wire, don't try to identify it by colour - believe it or not, some people have been known to use the wrong colours. Treat all conductors (even bare "earth") as live until you are sure they are not. Somebody once posted on this forum (or maybe Screwfix) that he'd solved the problem of supplying permanent live, switched live and neutral to a fan by using all 3 conductors in twin & earth.....

 

[Brentb]

If the fan has an earth, it should be connected. If it hasn't (i.e. it's double insulated, then there will be nowhere to connect it anyway, so just cut it off tidily and make sure the end won't poke anything it shouldn't.

Don't forget that if there is an earth it will also need to be connected to the supplementary bonding in the bathroom.

As for the other wire, don't try to identify it by colour - believe it or not, some people have been known to use the wrong colours. Treat all conductors (even bare "earth") as live until you are sure they are not. Somebody once posted on this forum (or maybe Screwfix) that he'd solved the problem of supplying permanent live, switched live and neutral to a fan by using all 3 conductors in twin & earth.....

Thank you. Yes, I believe it is a bare wire but is it normal to have bare earth and coloured earth? and if so, what do I do with them. (I promise not to come crying to you when my house blows up).

 

[il78]

may be the timer on the fan is faulty it is quite common.

Thanks, I'll check that, but the odd thing is it works better if it's loose a bit. When it's tight to the ceiling - as is should be, it runs without stopping.

Hang' on....I want to get back to this....If its tight to the ceiling it keeps running.....dont suppose you have screwed through a cable have you....

 

[Brentb]

may be the timer on the fan is faulty it is quite common.

Thanks, I'll check that, but the odd thing is it works better if it's loose a bit. When it's tight to the ceiling - as is should be, it runs without stopping.

Hang' on....I want to get back to this....If its tight to the ceiling it keeps running.....dont suppose you have screwed through a cable have you....

Good thought. I'll check.

 

[ban-all-sheds]

Thank you. Yes, I believe it is a bare wire but is it normal to have bare earth and coloured earth? and if so, what do I do with them. (I promise not to come crying to you when my house blows up).

In a bathroom, yes. If the old fan required an earth connection, then it would have had the (bare) earth conductor from the cable supplying the L/S-L/N, and it might also have had a supplementary earth bonding conductor, which would be a single core, insulated in green if old, green & yellow if new. Is it one of those colours? Is it single wire, larger than the others, with a stranded core? Can you see other wires like that clamped to pipes/radiators/towel rails in your bathroom?

 

[Bas]

- believe it or not, some people have been known to use the wrong colours

To prove it I have just worked in a bathroom and sure enough the "earth" wire to the fan was in fact the live wire!

 

[Brentb]

Thank you. Yes, I believe it is a bare wire but is it normal to have bare earth and coloured earth? and if so, what do I do with them. (I promise not to come crying to you when my house blows up).

In a bathroom, yes. If the old fan required an earth connection, then it would have had the (bare) earth conductor from the cable supplying the L/S-L/N, and it might also have had a supplementary earth bonding conductor, which would be a single core, insulated in green if old, green & yellow if new. Is it one of those colours? Is it single wire, larger than the others, with a stranded core? Can you see other wires like that clamped to pipes/radiators/towel rails in your bathroom?

Many thanks, yes it is, but there are no wires clamped to radiators etc.

 

[ban-all-sheds]

Oo-err. You might like to think about doing someting about that.

Do a search on this forum for "bonding", you'll find all sorts of stuff.

I wonder where the other end of that separate earth cable goes?