Installing "whirlpool bath"

[Dan delaMare-Lyon]

Hi Guys (& Gals),

I'm about to order our new bathroom - figured I'd DIY it - as it's mostly simple stuff. We've opted to have a fancy whirlpool bath and humidistat extractor.

I'm going to take out the existing electric shower, as we've never used it. It's 8.5kw and on it's own run to the fuse box and on it's own MCB. I'm planning to use this wiring to power the bath pump/extractor.

Anyone see any madness in my method?

It's a 30A breaker - and afaict - the pump needs ~100w maximum anyway

- and e extractor is peanuts.

Thoughts?

Cheers Dan.

[John Rumm]

Sounds OK in principle. You would probably want to change that breaker for something smaller though! Both devices will most likely specify they are fed from a FCU with a 3 amp fuse.

You may find the fan more convenient to wire from the lighting circuit (as they frequently are). That would also give you access to a switched live should you want it to activate when the light goes on (although less necessary with a humidistat fan).

I just fitted one of the Screwfix humidistat fans, which I can report seems to do the job well enough, and is not too noisy at all.

[Lurch]

On Fri, 11 Jun 2004 09:07:08 GMT, Dan delaMare-Lyon strung together this:

I would be more inclined to wire the fan into the lighting circuit. Depending on the specifics of the fan depends exactly how you would do this but it would be easier than wiring to the old shower supply. For the bath I would either change the MCB to a 16A or fit a 13A unswitched fused spur on the end of the existing cable and run a length of 2.5mm cable to a switched fused spur outside the bathroom somewhere, probably on the wall behind the bath, and the wire the pump into this spur.

[Dan delaMare-Lyon]

Ta John - that's useful.

What sort of fan is the screwfix one? (odd question I know).

We've got an open vent (as in 2 brick high hole in wall atm) and that is wahat will be replaced by said fan - but the outisde edge is a big bit of steel built into the brickwork - which I am loathe to disturb unless I have to.

Cheers Dan.

[Dan delaMare-Lyon]

Lighting circuit has been suggested twice now - only downside of this is that the ceiling bends with the roof - so I don't really want to start digging holes in it - thus the question about using the shower supply - as it's already in the floor - and I can just channel it into the wall to get up to the fan.

Think I'll poss drive them both off the same supply - with a well fused arrangement. Actually - thinking about it - there's the downstairs sockets ring in the floor in that room that provides a spur to the downstairs utility cupboard - so I could spur that with a fuse to the fan - that would take away the lighting circuit/ceiling issue - and use wiring that I can get to.

Then downrate the breaker on the old shower circuit - and use that with a ceiling mounted switch (as per the existing shower) and an inline unswitched fuse - to drive the pump for the bath.

That should work out OK - or am I a raving looney?

Cheers Dan.

[Lurch]

On Mon, 14 Jun 2004 12:21:57 GMT, Dan delaMare-Lyon strung together this:

Nope, you can't have two spurs off of a spur. If it's easier there's not a problem with taking a fused spur from the old shower supply before it reaches the bath isolator.

Yep, other than what I mentioned above. I'd stick a 16A MCB in the CU then you can run 2.5mm cable in for the new bits to the spurs, it's a bit easier to work with!

[Dan delaMare-Lyon]

I didn't word that right - the sockets ring main is in the floor - and there's an unswitched fused spur that feeds a twin 13A socket in the utility cupboard. I can spur off the ring was what I *should* have said and quite plainly managed to not put :)

Otherwise can spur off the shower supply - wait until the floor is up and see what the easiest route is.

Yes - we like 2.5mm - anything more than that and I start to curse a lot and end up upsetting SWMBO :)

Cheers Dan.

[Lurch]

On Tue, 15 Jun 2004 08:54:50 GMT, Dan delaMare-Lyon strung together this:

Ah, gotcha now!

Yep, sounds best.

That's not a good thing to do at all, aparrantly!

[John Rumm]

Errrm - what do you want to know? ;-)

It's a white faced box - protrudes say 3 inches from the wall. Back connects to a 100mm inside diameter pipe/duct. Feed mains into it via an isolater and a FCU, and off it goes. They have standard lightswitch operated ones with overrun timer. I went for the Humidistat version and did not bother connecting up the light switch operted connection. Thus it only comes on when the humidity level reaches the preset. There is a knob on the base of the fan to specify what RH level the fan kicks in at. The noise from it is not unlike a that from a modest PCs power supply fan - the sound is mostly "airy" rater than being motor or vibration generated.