glow-worm flow switch problem and leak?

Thanks for that, it sounds like that is the prob. the flow switch is ok now, i just took the board out and put it back in and it works!? however i cant seem to find this vessal valve.
there is a small blue ball shape on the left about the size of a tennis ball. then on the right there is a copper looking cylinder only about the size of a half pint bottle. either way i dont see any valve. The only other thing is if its behind the main panel where the pilot light is above the prv and circuit board and such?
thanks again

neil
April 2007

dont change the blow off mate, it sounds like the expansion vessel needs re-pressurising. there is an expansion vessel at the back of the boiler. inside this is a diaphragm and this expands and contracts against the air when the water gets hot . the expansion vessel is similar to a car tyre it will lose its charge over time. when this happens and your heating is on the water has no where to expand and the pressure builds uo and eventually will blow off. this explains why the pressure is rising. then when u turn your heating off the pressure has dropped. to resolve this problem you will need to de-pressurise the boiler, maybe through the blow off , and then get a foot pump on the expansion vessel shraeder valve. pump the pressure to about 1bar then re-pressurise your boiler. this should cure that problem. as for the flow switch, you can test this by linking it out and the boiler should fire.if your happy the flow switch is ok then look else where. it does sound like a loose connection or maybe a board fault. just isolate the boiler and get into the board and just make sure all the wires are connected. i hope this helps you good luck

EXPERT
April 2007