Potterton Suprima Fault

Hi there,
I have a suprima 100 that ignites an a random basis.It stays going for about a minute then stops and re ignites after about a minute. I have disconnected the timer but no luck. I changed the pcb for another one but not sure what the condition of the "new" pcb is as the problem still persists. Any ideas???
Regards,
Scott

That's how my Potterton suprima 50 works.If you look in the inspection window the gas only comes on for a few seconds then goes off again.Do you have enough hot water?

Hi I think it's a fault alright it comes on and heats the water even if the timer is turned off!!

Ah right,I thought that it was when the timer was on.

you should get a qualified gas service man to look at that.