Vokera Combi - switching off water supply
 

Hi,
I have a vokera compact 24, and I need to cut the water supply to it
to cut the hot water supply to the bathroom so as to remove the sink
etc.

There is a stopcock behind the washing machine on the cold water feed
and I could use this. I notice there is also a black stopcock, part of
the boiler, just where the cold water feed enters the boier, can I use
this instead? Access is slightly easier. Maunual does not state if this
is for cutting the cold water supply to boiler.

Thanks