Bathroom fan wiring puzzle

IM

The extractor fan in our bathroom has been rattling for a while, so I decided to replace it before the cold weather arrives, and leaving a window open gets less appealing.

I bought one marked up as 'pull cord', thinking that this meant it was designed for a ceiling-mounted pull switch (which is what we've got). In fact it had an integrated pull switch with a wee cord attached to the unit itself.

I connected it up anyway, figuring that leaving the ceiling switch 'on' would allow me to use the switch on the unit (or vice versa).

However, when I connected it up, no combination of cord pulling could get the fan going.

I took it back to the shop, believing it to be faulty unit, and ordered an alternative (non-switched) online.

I wired this one in this weekend, but still no joy - which makes me think there must be something I'm doing, rather than a second faulty item - but I'm !!!!!!ed if I know what.

It couldn't be a more straightforward connection - connect the live and the neutral and turn on - but nowt happens.

If I reconnect the old one, it works (albeit rattly) so the power is getting to the unit.

I've tried swapping the two wires, just in case the cable from the ceiling pull-switch was crossed.

Any clues?

r2015

Does it have a third connection for run on?


I replaced my bathroom fan and it needed 3 wires, the old one only needed two.

IM

No, just the two...

MX5huggy

Is it 12v? The old or new?

IM

This is the new one.. http://www.extractorfanworld.co.uk/st100b-silent-tornado-hi-power-bathroom-fan-3431-p.asp

I'd need to check the old one, tonight. Would it be obvious (i.e. written on it somewhere)?

IM

Looks like it is...



What's the implications?

andyhop

IM wrote: »

Looks like it is...



What's the implications?

That is a low voltage 12v item. You will have a transformer somewhere

Where is the fan located? Usually SELV fans are fitted within splash areas so I'd suggest fitting like for like or moving the fan location

IM

No, it's not in a splash zone.

It used to be, but since we remodeled the bathroom it's away from the shower area.

So, assuming I find a transformer up in the loft, is it just a question of disconnecting it and I'm good to go?

andyhop

Yes

Axial a will only push air around 1-2m in a straight duct. If your duct is over that then you need a high flow extractor such as a DX200 or XID100 fom xpelair

zax47

You need a 12V fan. SELV (safety extra-low voltage) 12V devices have been required in bathrooms for a while now, especially in zone 0 & 1. 12V transformer will be in the ceiling void somewhere - if upstairs then go in the loft and you'll find it.

Be aware that making a change to 240V fan a) requires the circuit to be protected by an RCD back at the consumer unit and b) will <technically> be notifiable under Part P of the building regs.

Save a lot of hassle by getting the 12V version of that fan.

Myself, I'd give that existing one a good clean first - it's a good quality fan and unless the bearing is knackered it could go on for ages. Muck on the blades puts it out of balance and then they scrape the casing.

I've fitted a few, they aren't cheap but they are good - persevere with it.

http://www.vent-axia.com/range/va100-selv-12.html