I have a Worcester Bosch 280 combi boiler. The pressure on the scale is way past 4 bar. I have reduced the pressure once back to 1.5 and made sure the filling loop is shut off, but it has crept back up. There is a screw valve where the loop joins the pipe into the boiler, but i cannot for the life of me turn it off! Have looked at other posts, but still not sure what to do.

Mick., January 2007

Make sure the valve is turned off by aligning the screw slot 90 degrees to valve body. (slot across the valve for closed, slot in line with the valve for open ) then bring the pressure back down to 1.2 to 1.8 bar.

Plumb Bob, January 2007