"Set Square" wrote in message
...

Some modern cisterns apparently have internal overflows - which flow into
the pan.

Have you actually *tried* holding the float down to see what happens?
--


Yes, I did and the level reached the lowest part of the cistern rim (why on
earth do they have semi-circular cut out on the back?) and began to
overflow. I tried again with a bucket and this time added water more gently
and it seemed to cope. There is some form of internal overflow through the
siphon into the pan but it would only deal with a leaking valve - certainly
not a complete failure.

The AS design was much better imo. I'll have to hope that modern valves are
less likely to stick open due to sand/soil in the supply following works -
that happened with my compact silent valves a few times.

Thanks