Hi there,
I installed my Nest thermostats last February (not sure the model -- basic model with no color screen). They worked flawlessly all winter, even with no c-wire for power. When the furnace was not being used as much, I was getting the low power issue. I installed c-wire to the NEST and that solved the issue. Now, months later, I turned the heat on and I'm not getting anything (I have a hot water radiator system). I have one old thermostat in the house in a zone that still works fine to engage heat (so it tells me the system is working fine to produce heat). In my case, the Nest engages heat control valves to kick on furnace -- that isn't happening. The Nest says heating and gives a 1hr30min estimate, but nothing kicks on like it used to. I tried factory reset, nothing. I changed out a motor on the flow control valve -- still nothing, so it tells me it wasn't a burned out valve motor (as is common). Any suggestions?
