I have used it for a year, but today i found it was dead.
At first nest (mounted on wall) showed no power and error code H72, so I checked the heat link, no lights were on. I checked 230v power supply of heat link and it was OK.
I opened the cover of the heat link, and supply power with the micro USD port, then all lights on but it still cannot charge the nest itself. Nest went out battery soon. When I pulled off the micro USD cable, the heat link was dead again.
I think something inside the heat link is wrong. What can I do?