After the heating has been on for 10 minutes pressure goes to 2.5 bar and starts flashing?

dave, September 2010

If the pressure goes up only when heating is on than pressure vessel is not working correctly. check air pressure in the vessel only when system is depressurised and should be just .9 bar and if not than fill to .9bar. or vessel is damaged inside and than replacing or install another on anywhere in the system.

Mr k, September 2010

hi there pressure is to much its a safety issue that kicks in to cut of the boiler try reducing your pressure to 1.0 to 1.2 bar when the heatings cold as there pressure rises once the heating is on then it shouldn't go over 2 bars you can take water out through the bleed hole in the rads as this will reduce pressure gl

kash, September 2010