Water stopcock

Seasalt3

Is it a good idea to turn water off at stopcock if going away for a few days and if you do turn it off can it cause problems with gas central heating boiler.

vacheron

if you turn a stopcock that you don't regularly use, it' most likely start leaking slightly when you turn it off, or back on again. 

So it does remove an unlikely risk, but could add a little inconvenience. 

Unless your CH boiler has an automatic pressurisation system, or is a vented system with a bleeder tank, I can't see how it would be affected, and I can't see how any system would have any problems for just a few days.