[mhurron]

Think about what you just said. Redundancy for a thermostat. You know, that thing that before the Nest you never even had to think about.

[bcook]

Perhaps not, but I have lost power for a week during a blizzard and it was nice to have a fire-place (redundancy). Disregarding the power-loss scenerio, if my any part of my HVAC system fails, I have space-heaters.

[cjensen]

tcdent didn't say redundancy for a thermostat. For example, a fireplace and some wood is redundancy that covers both thermostat failures and power failures. If you live in dangerous weather as mentioned in the original comment, it would be stupid not to have a Plan B.

[nulltype]

The thermostat at my place works great. That wasn't enough to keep the heater from breaking for about a week around Thanksgiving.

[CamperBob2]

Redundancy is already built into many home heating systems. My heat pump has a backup furnace for emergency heat (which is also used if it's too cold outside for the heat pump to work efficiently.)

So the hardware is solid enough -- it's just up to the thermostat to not drop the ball.