potterton netaheat profile 80?

Having a problem for the first time of this boiler.I have no idea of how old would be this boiler.now gave me a problem as there's no hot temperature on the radiators. changed pump and solved the problem,theres a heat of all the radiators BUT 2nd problem appeared like the boiler keeps heating it up for ten minutes and it was really hot,control set only at one then after that it turn off forever as in theres no sequence.I can lit up the boiler when pressing the reset button.Advise how to ammend this problem is highly appreciated.

rodel
September 2010