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 outside the four mark, 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.

Rahul Patel, February 2008

Your boiler has been overfilled with water - hence the pressure gauge reading to high. The simple way to do this is to open a radiator bleed valve and catch the water that squirts out, but be patient as you'll have to remove a pint or two until the black pointer comes in line with the red one.

John, February 2008