mick says...
On Thu, 17 Jan 2008 13:03:39 +0100, David in Normandy wrote:

RobertL says...
On Jan 16, 9:46*pm, Skipweasel wrote:
In article ,
says...

Ideally if the butt runs dry then the supply needs to switch back
to mains water (either manually or automatically).

I thought about doing that, but it was ridiculously hard to comply
with the water regulations. If it were as simple as a double
non-return valve I'd have done it, too.


Does it need to comply with the water regs if it is not directly
connected to the water supply? I mean, does connection to the sewer
mean it has to comply?

Suppose you fed the loos ONLY from the water butt and also had a ball
valve in the water butt so if it got very low it was filled form the
mains.

Robert


I guess that would be perfectly legal. May be worth considering.

Especially if the ball valve was fed via a n/r valve or 2. With the ball
valve near the bottom of the butt it would make a very nice automatic
changeover system.



Yes, I think I'd need to buy a quality UK ball cock & valve
though, not one of those plastic / polystyrene French ones
which seem to fail after six months.

The thing is, most of the time the ball cock would be
submerged under several feet of water, so there would be
quite an up-force on it which could sprain or snap a cheap
mechanism.
--
David in Normandy