If the bar is below 1bar when the system is cold ie not running the system is fine and does not need worring about. If the bar is below 1bar there is a black valve open it until the bar is back to 1bar.
If the is open for to long the bar will go to high and you need to bleed a rad and let the water come out.
If the is open for to long the bar will go to high and you need to bleed a rad and let the water come out.
