Sorry, but Nest sucks. Was told mine was out of warranty and nothing
could be done. My old fashioned thermostat worked. Bought an Ecobee and
it works. Why would the Nest not activating the reversing valve. I now
have an expensive paperweight. Will do...
Seems to be a common occurrence. Can’t find a fix for it. Put the old
thermostat back in, and it works fine. My HVAC guy’s recommendation was
to keep the old style thermostat.