A collegue of mine is due to lose his mains water supply later
> this week (Thursday) during essential maintenance by water
> authority contractors. The water will be off from 08.00 Thursday
> until 20.00 on Friday this week. The works involve replacement of
> the complete water mains supply pipework in the street, up to the
> individual valve outside each property.
>
> His house is fitted with a combi gas boiler. He is unsure if he
> will be able to run his combi (for heating only) whilst the water
> main is off. I am unable to answer this question, I am not
> a combi user myself.
Combi should continue working fine for heating. It would probably be a good idea to switch off its hot water facility whilst the work is going on so pressure changes and air in pipework don't cause it to fire up, and/or switch off the water at the mains.