I found the Google nest support chat line. They were very, very good
They advised things to try and get the problem resolved and when nothing
worked they replaced it
My Nest thermostat stopped working last night and showed code 71. I
checked the heatlink. There is power going to it but no lights. I tried
resetting but nothing happens. Looks like a fault with the Heatlink
itself. Boiler switching temporarily bridg...
