how to get pressure up i worcester 24i combi boiler?

You repressurise your system by opening the 'filling loop' - thats the boilers connection to the house mains water supply. Usually the filling loop is a flexible braided steel pipe with a valve on it.....on some newer boilers though the filling loop is inside, controlled by a plastic key. Don't overfill your boiler, and don't add cold water to a hot boiler.

John
March 2008