Mmmm,not sure, but I don't think so! was under impression you simply turned the white plastic key sticking out the bottom on the RHS and hey presto! Sadly nothing happens.......
I've managed to build a new place almost entirely myself and now can't remember how to top up the *+?@~ boiler!!! Its a Worsceter Greenstar 42CDi - has anybody out there got a diagram or whatever and that can help me out?! With thanks........