Trying to connect Nest Thermostat to older oil burner with zone valves connected to thermostats, no controller board with C wire terminal. Thermostat cable has two wires, red and white. Tried using external 24V transformer with one leg to the Nest Thermostat's C terminal and the other paired with the red into the R terminal. Getting No Power E297 error message. Any suggestions. I have a Nest Learning that works fine as it apparently doesn't require the C wire.
Thanks for reaching out. I'm sorry to hear that you're having an issue with installing the 24v transformer to your Nest Thermostat. I'd love to know more about this and I have a few questions:
If you have a multi-meter could you check if you can read 24V on your C wire?
Apparently the basic email reply doesn’t work. In response to your first communication; I get a ‘no power’ reading on the device. I have no C wire on my burner, just the red and white for heat. I had read that one could use a 24V transformer to supply the power. I purchased one and attached one wire to the C terminal on the thermostat base and the other paired with the red wire on the R terminal. The device then showed blue indicator on R and W and amber on C. Again ‘no power’. The transformer is putting out 24V, but I will admit that the gauge of the wires is rather thin. Chatting with Google the agent said this configuration would not work and I needed to use their power connector. From my reading of the material on this device, it won’t work in my environment either. Thanks for your help with this.
Thanks for the update. I'm sorry to hear that the 24V transformer isn't working with your Nest Thermostat. Let us know if you have other questions and we'd be glad to assist you.
@Fwg just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know.
I appreciate the help, Edward and Mark.