When central heating is on, the pressure bar rises from 1 bar to 4 bar and water starts dripping from the expansion tank. I have removed air from everwhere yet the pressure does not drop, and water continues to drip from the expansion tank. How do i reduce the pressure? Help me please!

Ali Dawood, December 2007

Pressure should never reach 4 bar. Pressure relief valve should lift around 3 bar. Can only assume that bar gauge is out of calibration. Pressure rise would indicate expanssion vessel requires replacement.

D.R., December 2007