Had the nest thermostat for about 2 years. Cost about £180 for the unit and about £100 to install. The thing is ok, reads wrong temperature, signs out of WiFi randomly. But it is liveable as it connects to Amazon and thus is voice activated. Essential for my disabled partner. However this am the heatlink just upped and died. Contacted customer support. 45 mins on a chat, arguing that it needs replacing. Just out of warranty so they were reluctant. negotiated them to send one out and refund me on return of old unit. I , of course , will have to pay for the installation. No refund there.Not too bad but the problem is this issue is widespread. They know it. Yet still sell the same unit. Now google are huge. They could easily afford to use decent components and iron out this problem. Profit seems to come first for them. I will have this unit fitted but will be looking out for an alternative. Hive or Honeywell seem a better option. There is a reason this is the only Google "smart" product we own. There is also a reason this will be the last. Poor product that could be amazing if they cared a jot about their customers.