the pressure on my worcester 350 keeps dropping to zero, this happens several times a day, I have looked for leaks but can't find any, have you any ideas as to what I should look for now,

Geoff McGuire, April 2005

why is the burners not getting gas through to light the boiler

andy, September 2013

Hi my boiler keeps locking out with the central heating on. It seems fine when it's heating hot water. I noticed lastnight that the radiators got excessively hot and the system pressure peaked at just over 3bar (usually around 2bar with central heating on whenever I've looked before).
If I use the reset on top of the boiler it works fine again for a day or so. Any ideas of common faults? Any info will be greatly recieved.

Dom, January 2012

Check expansion vessel pressure, to do this drain the boiler and attach a pressure gauge to Schraeder valve on vessel if it is below what it should be pump it up with a bicycle/foot pump, if, however water comes from the Schraeder valve the vessel will need replacing you can either buy this as a spare part for the boiler or if you have space you can fit an external one anywhere on the system this is usually cheaper and easier depending on which boiler you have.

Mark 4, December 2011

check the thermister hw ok but rads poor heat thermister as for cutting in an out check the air pressure switch on the zag 16 board common 240 volts then nc and no when fan runs full

gas eng, March 2011

Hi,

I need a new card (left one) as there are two which has burnt out. As this is a plug and go can I get one from somewhere?

Cheers

Rik, March 2010

when I switch on my worcester 350 boiler the burners stay on for about 15/20 seconds before turning itself off. Everything else seems to be working ok but it means the radiators only get luke warm. Any ideas?

Steve, February 2009

I have a Worcester 350 Combi Boiler, it was working fine this morning but now the pilot light won't come on and the green light which indicates that heating is required isn't lighting. The fan sounds a bit rough aswell.

Greg, January 2009

the water may be relieving itself out the saftey valve, this is a comon problem with combi boilers. if the expansion vessel is flat, the water heats up with nowhere to go and the relief lifts, the boiler works fine until it cools and contracts, leaving the gauge on zero. it is possible sometimes to pump up the vessel to 20psi with a tyre pump, but correct procedure is a little complicated.

Iain V, July 2008

The pressure relief valve may be leaking.
Mine is, any idea where i can get a new one?
clive@cliver.co.uk

Clive Rowlands, September 2005

hi geoff watch the pressure gauge on the boiler after you have topped up to 1.25 bar when the heating is on max and you will probably find it reaches 3bar and over within half to three parts of an hour. if so drain the heating side of the boiler using the prv repressurise with a foot pump the heating expansion vessell to 0.7 bar .make sure the prv is held open while you are repressurising the vessell and the give the prv a good clean out before refitting and refilling the boiler using your filling loop to 1.25 bar. hope this helps

glenn, April 2005

have you looked at the pressure relief valve discharge pipe?

d.., April 2005