How can I fix my potterton profile 60E ?

I have the above boiler, its keeps cutting out and have to press restart button, tried a lower heat setting no joy, have replaced thermostat and overheat stat problem still persists, do get a noise from the boiler which sounds like a kettle boiling believe this is known as kettleing.Ten years or so ago change both the both fan and mother board have been changed
any ideas