Just built a new house and put in a 4 zone radiant heat system. This is the first winter of use. Each zone has it's own nest thermostat. The system controller is a taco 4 zone. Everything seemed to be going fine but now they are all complaining that they don't have a c-wire. They all do, and I measure 29V AC across red and C. I can see on settings that the battery is at 2.8 V so it is low, they seem to not be getting the voltage that my volt meter says is there. Any Ideas?
Thanks for reaching out. I'm sorry to hear that you're having an issue with your Nest Thermostats. I'd love to know more about this. Could you check the power readings of your Nest Thermostats? You can find this information by going to Settings > Technical Info > Power.
Hey there wtg,
Thank you for filling out that form! You should have someone from Nest Support reach out to you via e-mail in a few days, so feel free to continue the conversation over there. In the meantime, do you have any other questions for us here on the forum? If not, I'll go ahead and lock this thread in 24 hours.