wrote in message ...
On 31 Dec,
Andrew Collins com.hotmail@bflfcbb wrote:

On Sat, 31 Dec 2005 17:00:12 -0000, "Fentoozler" nospam@mapson
wrote:
The pressure relief valve is right at the back/bottom of a 240 (drop
the
control panel down to see it), and is normaly a red one with the
pressure
gauge directly attached (just trace the relief pipe up to find it). It
sounds like it is leaking, thus dropping pressure - flushing it though
may help (give it a twist, then repressurise), otherwise drain the
boiler and replace (again, twist it to drain fully, no need for mains
water isolation, DO NOT isolate the boiler via its own isolation
valves
as these WILL leak. Not expensive, part no more than £5, you can DIY.

Pressure valve located and duly twisted. Cheers!

I don't think it's made any difference though. I think it might be time
to
find a new valve.


If the pressure is rising rapidly when heating, then it is likely that the
pressure vessel has lost charge. It's easy to check but the system needs
to
be cold and not pressurised. You will require a pressure guage (car type
is
adequate) and a foot pump or similar to re-charge. About 10psi (0.7bar) is
normal.

Or a blockage in the connecting pipe system to expansion vessel