I think when we visit the house I’ll turn the water off at the mains and then run the tank dry. I wish I could empty the central heating system as well, but a check on the web suggests that is more complicated and probably not something I can do quickly.

Should reduce the number of leaks we could get, and at least if we do get a leak, it’ll only have a finite amount of water to dump into the house, after which it should run dry.

I wish I’d thought of this two months ago – but two months ago I wasn’t thinking about anything.