Oh, and the gas meter runs on a battery that is estimated to run for 10 years. No one realy knows what happens when it runs out.
I work in the industry, and I know: Most "smart" meters will disconnect the gas supply when the battery fails (a quick search also confirms this outcome for a range of companies in addition to my own).
The batteries are supposedly ten year life, I know of instances where they've failed after eighteen months. And due to poor design, most then need a complete replacement meter.
Smart meters: Utter shite - I wouldn't have one. The only scenarios they work for is where it is very difficult to get meter readings, or for pre-payment customers, where a PP smart meter gives a much better customer experience than the old style key operated payment meters.