Had a nest with a w5 fatal failure called Google , go through there tick box exercise and they agree to replace you have to pay 219 pound refundable when they receive it back , Got a replacement and that has a h71 fault 3 engineers and 5 hours later and change a heat link ,they agree it's faulty as well but CANT (I think they should say won't ) replace until they get the first one back , When they get the first one back to there waregouse in Poland then I can call them and start this BS process all over again , so I will be without a control for my boiler for about a month plus Google we only truly judge a company when things go wrong ,you are an absolute epic fail when it comes to putting customers first , I now have 2 faulty products can't operate my boiler and all you care about is getting your faulty useless products back You could learn a lot from Amazon and how they conduct business and sole problems I will never buy another Google product again