How do i stop the pressure on my worcester boiler 24i from dropping to 0 ev?

Your expansion vessel has either lost it's charge of air or the internal bladder has gone. you can leave the old one in place and fit an external one any where on the heating system. the type you want is a red one with a 1 bar charge. As long as the house isn't to big an 8 ltr one is fine. cost is about £25.

Tony G
December 2010