when central heating running the boiler pressure just keeps on rising until water is released from P.R.V. C.H.expansion vessel OK air pressure release OK water pressure switch OK when boiler cools water pressure too low. A quick flick of the topup valve and pressure OK until boiler ignites again and prosses repeats.
Thanks for info,I had tried repressurizing expansion vessel but still didnt solve over pressure,elbow in flexy pipe feeding expansion vessel was blocked with crude, did squirt dirty water everywhere whilst removing blockage with a piece of stiff wire, so beware!
Nick
October 2011
mine is also blocked but before i clear the blockage i believe the expansion tank is pressurised. so how do i prevent it leaking?
paul marsh
March 2008
problem solved would never have dreamed a flexi hose would get so furred up thanks for your advice greatly appreciated.
Geoff
March 2005
make sure that the tube to the expansion vessel is not blocked,should be a flexi hose,very common for blocking up where they join to brass manifold.
gas man
March 2005
If the radiators are not getting warm your diverter may be stuck. There are a couple of versions of the puma, you may have the diverter with a wax capsual or a motorised diverter. you say the expaision vessel is ok, but make sure. As it has operated a few times now, you should also consider changing your pressure relief valve
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