IMM wrote in message
...

"Holly" wrote in message
...

IMM wrote in message
"Holly" wrote in message



so why wouldn't it either not expand further in the first place
when
it reached that state, or simply suck the air/water/steam back
in
again??

When it boils it has to go somewhere, so it goes back up the cold
feed. With no water replacing the water moving back up the cold
feed

When the pressure ceases to be a problem why wouldn't the
water just stop moving back up the cold feed?

That is where is expands to, back up the cold feed. UK cylidners
can't
expand up there, and have either: aa air pocket that requires periodic
re-instating or an external expansion vessel.

Third and last try at this question. I now understand how UK cylinders
work. I now see the problems and possible solutions to the situation we
have here in our house. I'm just questioning your theory here. In the
case of the cold feed being open, when the pressure ceased to be a
problem why wouldn't the water just stop moving back up the cold feed?

the cylinder will implode.

I'm not saying that these cylinders can't or don't implode, just
can't
see why they would in this situation.

If water boils and it expands up the cold feed, which is at the
bottom, the
water requires replacing from the top, otherwise implosion.

I still think this is nonsense, "it's the law of physics Jim" but I do
accept that I could be wrong. Go on, convince me, when the pressure
ceased to be a problem why wouldn't the water just stop moving back up
the cold feed?

Holly