I have a potterton Boiler Suprima 50 (which has had the pcb changed about 12 months ago) How ever a new problem is no occuring. The boiler fires up, gas burns and then runs for 30 - 60 seconds at which point the main rcd in house trips. What is the problem and is it a known fault? My plumber is trying to sort it but seems at a loss......meanwhile my wife and kids (and me) are freezing.

MattChand, May 2010

9/10 times its due to a faulty pump

paul the gasman, May 2010

has he tried running the boiler on it's own without the
external controls ?
if it runs ok then you know it's not the boiler but an external control etc.
you got to eliminate one by one.

hi-spec plumbing & heating (essex), May 2010