I use Nest in a second home so i'm not able to get physical access to the thermostat right now.
There are 2 Nests in the home and one of them is working fine.
The other is reachable and shows a temp for 47F, the temp is on eco at 61F (i pushed eco up to 61 as part of troubleshooting) and the thermostat has not turned heat on -- (i.e. the background color is grey). This is the 2nd time that this issue has occurred, the first time i fiddled with settings (turning mode to off and back to heat several times among other things) and eventually it went away.
It's pretty cold at the house and i'm worried about the pipes (probably fine for now).
Is there a way to determine if the problem is the furnace or the nest?
How do I resolve?