I understand what you're saying Jeff. If one tstat fails, IE dies completely, not just probe failure, then the flexwatt isn't going to get power anyway because it can't get through the dead tstat. Yes?

I understand the use of a back-up in the case of probe failure, but when I have had probes fail on my Herpstat 2, the unit shut the power off to that half of the thermostat and definitely told me about it.. At 3am.. Loudly.

Do Johnson Controls or Rancos shut themselves off in the case of probe failure?