[john_b]

What failure mode would you want, if not off? Having a failed sensor+controller control temperature in any way isn't what I'd want. One could have a backup thermostat as a fallback, but I doubt their average customer wants anything that complicated.

[jellicle]

The problem is that a failure mode of "off", in the winter, in cold climates, means you come home to $30,000 of water damage and pipe replacement which probably won't be covered by home insurance.

The "fail safe" mode here needs to be "maintain moderate temperatures, neither burning nor freezing". Simple mechanical thermostats do this extremely well.

[venomsnake]

>Simple mechanical thermostats do this extremely well.

But they don't have api with which to auto post your daily temperature to tumblr. Or security vulnerabilities.

[ghaff]

I'd want it to failsafe to some sensible minimum temperature: 65 degrees F or whatever.

[Phlarp]

If the temp sensor is the point of failure, this "failsafe" would "fail not very safely"