seems my 3rd gen thermostat just decided to have a cold solder problem at the 20 PINS socket on the base unit a week after the warranty expired. Call support, no longer exist. Need chat. Attempt chat with more than 10 agents... they drop the chat, transfer to other queue, and couldn't get a single person to help. really feeling like a bad experience. User's recommendation: Dont use nest as when you need support , there is no support.