Hi,
Just done mine, you wont fix it with a gasket kit.
As you look underneath the boiler you will most likely see a small white plastic knob near one of the connections on the back, close this and drain the hot taps. (if its not there turn off your water supply and drain the hot taps)
Undo the 4 pipe connections and (if you have one, not all do) the fifth connection on the right hand side as you look at it, just above the pipe connector you have already undone.
Now, as you sit patiently looking at it you will find it is a little loose, hanging from the top. In front of you (above the bracket) is a small screw which holds it up, undo this and it will get looser then 'drop off'.
Take it to your nearest plumb centre or vaillant dealer.
They will happily give you a new one for around £100
Mark Butler, January 2008
