Ed Sirett wrote in message ...
Michael wrote:

I have a simple problem. Potterton Suprima 80 boiler. Problem since
new 1 year old. The boiler does not stay on long enough, I have temp
guage on the outlet copper pipe from boiler newer goes much above
60degree. I have had the circuit board changed, the temp sensor
changed, as recommended by various plumbers. Yet I have the same
problem. The temp control knob is on max. The same problem, the boiler
stays on for 2mins then goes off. Why does the dam thing not stay
on!!!

Anyone who has a solution, or have had similar problem most welcome to
contribute.

Check that the primary water is actually able to flow well - stuck pump?

No, the pump is setup for fast speed, if its med or low the heating
just gets warm. Only on fast pump does the rads warm up. There is no
air in the system as the plumber has removed it all. Still same
problem Temp control knob on boiler is set to max and the boiler does
not stay on enough to heat the water out from boiler above 60degree.