Hello all. During the last week I have gotten this same error twice and fixed it the same way each time, but I am worried that this is a symptom of something larger. I have a fairly new HVAC system (2 years old heatpump/ac combo) hooked up to a Nest. I get the same error in this post: https://www.reddit.com/r/hvacadvice/comments/15ulr9o/google_nest_thermostat_no_power_to_r_wire/
I have gone outside and shut off the power at the main house breaker to the AC unit (double pull switch) waited about 10-15 seconds and turned it back on. It clears the error and if I start a test using the nest for the cooling heatpump, it works just fine and cools again, no R wire troubles.
I came back home from a run and found it happened again today, and fixed it the same way after two attempts at the breaker.
I touched no wires in the process and did not pull off the nest and reseat it, so I don't think it is a wire contact issue considering it has been running with no issues for 2 years.
Would love some thoughts or advice on what to look into.