Same happened to me but i replaced it with one of those pushbutton kits from B+Q etc for about £19 works a treat and flushes much better. Only takes an hour at the most to fit.
I tested they way you did and the diaphragm was knackered, replaced it and now got hot water.
But i disturbed the coupling into the heat exchanger and the coupling now weeps where the inner tube slides into the coupling!
More messing about and the back of the valve now weeps where the two grub...
You live and learn !
Car industry is the same, buy a genuine spare, chances are the part you get from the guy from the corner accessory shop is from the same manufacturer.
cheers,
Found plenty of places to buy a kit for ~ £10 is it better to spend the £40 and get a new valve ? I presume then the repair will also work in a Worcester part ?
Cheers
Thanks for the reply, looks like my logic was okay.
I presume the diaphraghm 'drives a plunger' and so the microswitch.
Any suggestions on where to get a Gianonni repair kit.
Cheers
Have a Worcester 240 combi, Automatic air vent failed again and we lost hotwater but heating is ok. Water comes out of the chamber over the electronics and screws the driver board, what a crap design. So replaced board again as well. The whole start up sequence works fine.
Still have a...