Extractor fan advice please

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I have a feeling L2 comes into play,I have wired up my fan as in Dig 1. But would like to wire it up to Dig 4, which cable from the rose L1 or common? Or do I use L2 and put it in terminal 2?

 
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Sorry. I do not understand

You say Dig 1 and 4 but you have posted digs 3 and 4.

Also i do not understand the references to common L1 and L2. Tose are switch terminal markings. The ceiling rose will have loop N and L.

Post photos on here of the diagrams you are really talking about and also a pic of the ceiling rose.

It would be a great help if you could post the pics using the forum guideline so we can see the pictures in your post.
Here's how //www.diynot.com/forums/viewtopic.php?t=129539
 
There are many ways to wire an extractor fan which depend on where supplied from and type of fan and if there are windows and if those windows open.

When not required by building regulations running off the lights is common and in the ceiling rose you have a triple connector block plus earth and it is simply the double outside terminals to terminal 2 switched line, the triple centre terminals to terminal 1 permanent line, and the triple outside terminals to terminal 3 neutral. This of course will only work with fans designed to run on be it simple timer or humidity controlled.

When building regulations apply then if there is a window no longer can the fan be solely worked by the lights there must also be a way to run the fan without switching on the lights.

This then becomes more complex but you can use a simple push button and not have the lights connected at all.

Normally way is to use a double pole switch for the lights so although same switch there is no electrical connection between fan and lights.

Where the real problem arises is where the lights are not a standard ceiling rose with small spot lights it is common to use the switch as a junction box rather than the ceiling rose. But where lights have been retro fitted the junction box can be anywhere if in fact the installer has even bothered with a junction box.

In England and Wales the bathroom is a special area so in theroy there should be an installation certificate or a minor works certificate for any work done and if done by scheme member it will also have a compliance certificate and if direct through LABC a completion certificate. The latter in Wales did cost £100 plus vat last time I enquired so unless some really extensive work is being done then not really worth DIY.

They should check it complies with three Parts of the building regulations F, L and P. Not too much of a problem with balanced flue or electric central heating but any heating appliance which draws air from within the room can cause problems. Although I hardly every use my gas fire if I wanted to fit a bathroom fan it would likely have to be a heat recovery unit to comply with regulations which are far more expensive than a simple fan.

My house is not really a problem loads of drafts under front door etc. But my father-in-law with same design of house has had near every draft excluded and lives in a near air tight house triple glazing etc. As a result his humidity is far higher than mine and so he needs something to ventilate his bathroom far more than I do. But be it a bathroom fan or a vented tumble drier with his house there is a very real danger of drawing in combustion products from the gas fire.

Nothing seems simple any more.
 
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Your problem is that you will need a neutral connection to the fan(whichever diagram you wire to).

It is extremely unlikely that there is a neutral at the pull switch. The place you will probably need to wire from is the light fitting oitself. It depends on how that is connected up, but you should find live, neutral, switched live and earth at the one place. Assuming you have a loop-in wiring at the light fitting.

Post a pic of your light fitting wiring if you are not sure.
 

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