My old thermostat lasted 20 years and nothing went wrong with it. Google's Nest Learning Thermostat has finally expired after 2.5 years. And it cost an awful lot more.It started a couple of months ago with the wifi connection failing - seems that was a fault in the unit. Then there were sequences of it not connecting to the boiler and now, it just plain doesn't work - if I connect it to the baseplate it won't charge, if I disconnect it from the baseplate to charge it doesn't work. First Google product and will probably be my last. Really disappointing.