pressure problem?

i spoke with a friend who said to check the pressure vessel. he said to drain the pressure to nothing and then repressurise the vessell with a pump up to 1 bar.

i have done this and it seemed to work however the same problem has occurred 1 day on.

the pressure seems to drop below 1 bar when the heating is off resulrting in topping up.

i am now at a complete loss?

fear that if i leave it the pressure will go to 0.

have checked all rads and no sign of any leaks.

when the temp is on low the system seems ok it only when i increase this the pressure goes above 3?

any thoughts

lee
December 2009

when the radiators are cold what is the pressure in the system?

a1
December 2009