Worcester 24i pressure too high !!

[applet]

I have a Worcester 24i combi boiler fitted about 3 years now.

I know how to get the pressure to go up if the pressure is too low via the filling loop, but I have no idea how to get the pressure down if the pressure goes too high, as it just has done, from 1.25 (pressure should be 1-2) to over 3 = problem.

Curiously all this occurred just after I had to turn the water at the mains off (via the mains tap) in order to change tap washers, after which I noticed the boiler pressure going up and up and up... even though it had nothing to do with the boiler and noone went near it. Now the pressure, at the 3 mark, won't go down. Have tried bleeding radiators, and have heard overfill water outside emptying, for the last half hour but really, it's not gone down at all. (have searched through manual but no info on high pressure there either)

Please does anyone know how to get the pressure to go down?

[sunbeam]

make sure the filling loop isn't passing, better still disconnect it,

the pressure should go down when you bleed some water out of the rads,

if it still continues to rise when the heating is not on, then i'm afraid the heat exchanger in the boiler has gone.