drain some water from a drain tap on the heating system
mick the gas man
February 2010
under the boiler will be a blow off valve either pull or turn it and it will lower the pressure
paul
February 2010
vent the excess pressure out through a radiator bleed valve preferably close to boiler only so you can see/watch the gauge drop .(soak the excess water up with old rag )
ensure the filler loop taps are turned off properly and not letting past as this maybe causing the pressure rise. removal of the loop will confirm taps are o k