"Des" wrote:

Hello Des

D| I've just had an old Armitage Shanks toilet replaced with a
D| new Heritage Bathrooms model. The AS cistern had an

Ha! I've just fitted a Heritage toilet also. It's nice.

D| upstanding pipe which allowed water to run out the house in
D| the event that the inlet valve failed - which it did a few
D| times over the years. The HB cistern has no such external
D| overflow and as far as I can see, if I hold down the float
D| it simply overflows over the top of the cistern.
D| Is this correct, or am I missing something here?

I had this same question. The ceramic cistern has no hole for a
conventional overflow. The instructions for the flush assembly DO
mention an internal overflow but it's by no means apparent that what
you're given is such a beast.

However... When I hold down the ballcock on mine to simulate an
overflow, water DOES drain down to the pan (as per the new regs that
allow an internal overflow). I have absolutely no idea how it does
this - there's no physical difference to the assembly compared to a
normal one, but it "just works", so I stopped worrying about it. It
doesn't drain enough to cope with a full blown entry failure, but then
- a 21.5mm conventional overflow often wouldn't either.

Mine, and I suspect, yours - are internal overflows that will cope
with a small volume of water which is adequate for the majority of
"leaking" feeds.

It could be you don't have the internal overflow gubbins inside, or if
you "had it fitted" the plumber substited it or somehow messed up the
fitting. I can confirm, though, that HB supplied mine with an internal
overflow which works through some kind of magic.

Hold down the float to raise the water level until it's about to flood
then check the pan, I suspect you'll see water trickling down.

--
Simon Avery, Dartmoor, UK
uk.d-i-y FAQ: http://www.diyfaq.org.uk/