My Boiler started losing presure going down to 0 bar.... I topped it back up but kept going down.... Now it's gone the other way it now gone up to 3 bar when off and over flow pipe is leaking,,,...... How/Why????

C Jones, March 2007

There is a fault on your boiler expansion vessel.
either it has no air or diapharm is split.
Check the air filling point is on the top. it is like a tyre air filling valve. press it if water comesa out it is split if little bit of air comes out you need to fil air in it up to 10 psi
IF WATER COMES OUT YOU NEES TO REPLACE THE VESSEL.

HEATINGDOC, October 2007

i would say your filling loop is not shut /shutting fully it can't keep going down then suddenly go up try disconnecting it or shut main stop cock and get pressure to 1.5 bar and run your heating if it don't move up your loop is letting by.

hi-spec plumbing, March 2007