I have a two-wire, heat only system. I installed the Nest thermostat and it worked fine, except for the N260 error. Per Google recommendation, I acquired a Nest Power Connector, instead of installing a "Com" wire. I followed the instructions to install the Power Connector. After completing the installation, the thermostat indicates "No Power". Per instructions, under settings, I tried to conduct a test of the Power Connector. I get the message "Unable to test. Please try again later." No other error codes. Contact with Google tech support was unhelpful.
