I have a Worscester Bosch 240 and the central heating has just gone off. I did all the usual stuff like oprning radiator thermostats, turned up the temperature dial on the boiler, switched it no 'on' permanently but the pilot light is stubbornly off. However, having given up as I couldn't see anything else obvious to press or prod I turned the hot tap on and lo and behold the boiler sprang into life.
So with the hot tap running I have the pump running and hot water coming out of the 2 'hot' pipes from the boiler, and I could feel the hot water starting to get to the rad. But as soon as I turn the hot tap off the boiler switches off.
I've trawed the forum and with the opposite problem [hot rads and no water] the suggestion seems to be a diaphram or a 'diverter valve'. Could this be the problem here too? Is there a work-around, even temporary, to force the heating on - 'hotwiring it' I guess, as it's getting chilly and I won't be able to get parts or an engineer until next week.
As to parts, is the diaphram and/or diverter valve a DIY fix? I'm fairly handy [build cars for a hobby], but not to keen on messing with gas. And if it's just water/power I have to turn off, do I need to bleed anything afterwards. Sory to be dense here but I've never seen inside a boiler before and have no idea what a diverter valve is or where it sits in the boiler.
PS - where do I get one from? Trawl the 'net, or is this a common part the local plumming emporium will have?