how to turn water off to hot water bath tap to fix spindle?

Hi
Have a problem with my hot water bath tap in that
when you undo it hardly any hot water comes out.
Had the same issue with the cold bath tap and it was the spindle which came off but the cold bath tap had its own isolating value so was able to turn off the water to it and fix spindle.

how do i turn the water off to fix the hot water tap ?
I have a combi boiler in that when you turn on hot water it fires up
If I switch off the boiler will water still flow to hot water bath tap ?

the cold tap had a isolating value but the hot water bath tap doesnt ?
Any help with this greatly appreciated.
Many thanks.

Read more: http://www.diynot.com/forums/plumbing/hot-water-bath-tap-spindle-has-come-off-cant-turn-water-off.378394/#ixzz2gTvWemmP

Phil
October 2013