HI. CAN YOU HELP. I HAVE A POTTERTON SUPRIMA BOILER AND DRAYTON LP241 CONTROLLER. WITH HEATING AND WATER SWITCHED OFF, THE BOILER KEEPS WORKING ABOUT EVER 5-10 MINUTES. IT IS ON THE WATER SIDE BECAUSE TANK IS HOT. I HAVE TURNED THE TANK STAT TO MIN AND REPLACED THE LP241, BUT BOILER STILL OPERATES. ...
