No warning codes and heating and hot water are fine.
When the boiler has been fired up for 30 minutes or so, the pressure dial goes just beyond "3".
Is there a fault ?

Malcolm Cutt, April 2013

Sounds like leaking expansion tank to me,if topping up regulary.
With no pressure in system and heating cold, see if water comes out of expansion tank when shreider valve
core is pushed open.(it will need re pressuring) If excessive amount of water comes from tank, tank may need changing.Pressure safety valve should generally blow off at around 3bar.
The system pressure wants to be set around 1.25bar when system cold. Dont know exp.tank press.

spooney59, April 2013

It's not serious problem but could get that it will pass 3bar and through water out via pressure relief valve ,problem is with pressure vessel need to pump air to required bar refer to manual ,empty to do re pressure

ltd, April 2013