I hope you can eventually get me to the solution here. The pressure gauge on my combi boiler (Vaillant ecoTEC plus 831) was low so I let the water flow into the boiler (taps for this was behind a cupboard near the bolier). But the gauge went up very fast and when I closed the tap the gauge indicator went up to the red area.
Can anyone advise how to let the pressure out so that the pressure gauge is back well within the black area?
Can anyone advise how to let the pressure out so that the pressure gauge is back well within the black area?