On Tue, 06 Jun 2006 21:56:26 +0100, David Hansen wrote:

On 6 Jun 2006 13:07:41 -0700 someone who may be "Pablo"
wrote this:-

Much appreciated. I turned the hot water on and watched the tank to see
what happened. There was a continuous steady flow of hot water from the
vent pipe into the expansion tank. It showed no sign of stopping. Very
disconcerting. I have now shut the system down pending a plumber
visiting on Wednesday. I had a new pump fitted two months ago. Perhaps
they set it too quick.

Can the pump speed be reduced? Normally there is a switch on the
pump.

Yes but as I said in my reply to the original post this is only a
workaround. The system needs the geometry of the pipework correcting or
possibly converting to a sealed system. This is only possible for boilers
with an integral overheat cutout. This would probably cost in the
region of £200. [Ducks barrage of 'my mate would do it for 50p' posts]

BTW to the original poster ('Pablo'), please follow up your posts by
replying to a post in the original thread you started rather than starting
a new thread. That way all correspondence on the subject stays grouped
together.