Nest N260 error code and the C-wire
I have a basic heat only furnace (gas/hot air), and there are only 2 wires feeding the thermostat - one red and one white. So when I tried to install the new Nest thermostat, it indicated that I needed to get the free Power Connector, which I did. It was a simple install and it worked for awhile, but then this N260 system error keeps coming up. Google help wasn't all that helpful, and told me I should get an authorized HVAC contractor to fix the problem. It's only a few simple wires, so I think that's ridiculous, so before I return it to Lowe's, I thought I'd reach out here to see if you guys have any ideas on how to fix the problem. See attached pics, and note that for some reason may years ago someone switched the red wire to a black one, and it works just fine with my standard non-smart thermostat. Thanks in advance for any help you can provide.
