Old extractor fan 2-core New fan needs 3 wires

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Hey,

Skip down a few paragraphs if you don't want the back story!

Long story short - we've had loads of little issues, mould in most rooms, heating wasn't serviced, mice in the kitchen/loft. Mostly fixed, the mould being my favourite. Ass clown vendor (AC) who we bought off clearly whitewashed the walls, including bathrooms and never had the heating on which explains that.

House is 70s, extension maybe 7 years old and both ensuites are in the extension.

The fans inside are badly placed, rather than being over the shower are behind a beam or on the other side of the room :eek: and both have about the same suck as asthmatic ant after a particularly bad chest infection. In summer this wasn't an issue you'd just open the roof window, in winter the rooms fill with steam and never get close to clearing.

So in my haste to buy everything I needed for my ever-growing snag list I grabbed 2 extractor fans a few months back. Outside of the return window by now, I decided to fit them today, I've put it off long enough



My first issue, the outside vent fell off as it was held in place with a tiny strip of ptfe tape. Not expanding foam, not silicon, not even screw like you'd expect...no ptfe tape holding it onto the pipe inside. Which isn't even all that great a fit. Better weather and I'll fill the gaps properly

Anyway...

Second and the far bigger issue is that the old fan has a 2-core wire
64a1b062-2f9a-48a3-acfb-e8621b2d2c8e.jpg df673321-7731-442c-97d0-04df2d2fbf08.jpg

The new fan needs 3 wires...

8d22e8c8-db08-47ac-aacd-1c67f77a96c7.jpg

I'm happy enough to do basic wiring or call in a sparky if needed but I have 0 idea where to start on this one!

Do I spur the live into 2?
Do I need to get it rewired from the isolator on the wall, which in itself will be an issue as it appears to be plastered into the wall.

I have tried the blue in both top connections and it doesn't turn on

I'm currently very glad I started in the bathroom that gets the least use :cry:

Thanks for any advice!
 
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EDIT. The wiring at the old fan is 12v.

There may be a good reason it is 12v, if it's too near the bath or shower.

There will be a transformer somewhere, this transformer will determine if the fan has an over-run facility...
 
Other things to consider are if the new fan would have to be 12v, depending on it's location.

If your new 230v fan will be suitable in that location, we then need to know if you need the over-run facility, as some rewiring or wiring alterations will need to be made.
 
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So 1 is the opposite side of the room to the shower

The 2nd is outside of the shower enclosure and behind a roof beam

I'll check what I think is the transformer in the morning!

The old fan had an overun too.
 
Spoke to my sparky, he told me to run an extra wire off my live and it'll work, but he'll come and do it properly in a week or two.

Having seen some other bodge jobs round this house I've decided to have him check it out.

Thanks all
 
There is always the frequently done alternative, remove the timer board from the fan and mount it in an enclosure where the current 12V transformmer is located.
 
As Sunray says, use the transformer box as a junction box - remove the guts from the transformer box and connect the switch live and neutral (230v) to cable that goes to the fan. Terminate the unused permanent live in a separate connector block on it's own.

At the new fan, link L and LT with a short piece of wire.

You won't have the over-run function, but there you go.
 
As Sunray says, use the transformer box as a junction box - remove the guts from the transformer box and connect the switch live and neutral (230v) to cable that goes to the fan. Terminate the unused permanent live in a separate connector block on it's own.

At the new fan, link L and LT with a short piece of wire.

You won't have the over-run function, but there you go.
remove the timer board from the fan and mount it in an enclosure where the current 12V transformmer is located.
that way the switch live, permanent live and neutral are connected to the three terminals (that are currently in the fan) in the normal way and the existing T&E is used as a link between the timer board and the gutted fan (just like between the 12V transformer and fan).

This will involve effort and possibly soldering etc.
 
All very good advice and I have less and less of an urge to tinker with it!

I haven't had the time to dig into the transformer on the wall, I will take a look this weekend at some stage, but I am leaning into letting my sparky do it properly
 
Provided that you are only concerned about the humidity rather than "smells" you could just use the two cables and ignore the switched live. My humidistat fan doesn't "have" a switched live because I didn't want it turning on with the ceiling light. That said, I did add a switch in a cupboard to fake a switched live if I need to get rid of smells.
 

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