Boiler is showing no error codes is set at factory setting of 75c but is over heating getting to 95+before shutting down rads red hot pressure building to 4 bar. Changed flow stats and control panel Checked expansion tank any suggestions as to the problem There is a High limit thermostat but I can`t find any one who can supply as new one. Adjusted boiler temperature to 60c still the same

John T, September 2015