The pressure gauge (a dial) has two pointers, a red one and a black one. After the last service on the boiler, I believe that both pointers were on the figure 1, but now the black pointer is almost down to zero, although the red one is still on 1. Is this something that I should be concerned about? I don't know how to modify the pressure.

Marion Ellis, January 2008

the pressure dial is on 1 how do i make it go up

john, September 2013

What if the Black bar is on 1 and the red one's on zero?

Al, April 2008

One of the pointers (the red one, by the sounds of it) is movable by turning the gauge itself or a small wheel in the middle. Leave that on 1 bar, as it is. The other one (usually the black one) tells you the pressure inside the boiler. You need to bring the pressure back up to 1, so both pointers meet. To do this, your boiler has a 'filling loop' - usually a flexible pipe with a tap on one end- and this connects the boiler to the house water main. You need to find this filling loop, and open the tap slowly, watching the pressure gauge rise as you do so, until the pointers meet. (Don't overdo it - or you'll have to bleed water out again). The tap, by the way, may be either hand, screwdriver or small spanner operated. Fill the boiler with the central heating off to get an accurate reading. Hope this helps!

John, January 2008