No power to RH wire Nest Gen 3

[wjp039]

I have a 3 thermostat system in a home that is less than 5 years old.   I recently installed two gen 3 nest thermostats, no issues.  I picked up a third, and I am getting E74 No power to Rh wire only on this 3rd thermostat.  I checked the two air handlers (one basement, one attic) and the fuses are fine.  I tried two different base plates.   No change, getting same error.  The other 2 thermostats are working fine.  HELP!

[Houptee]

Does the 3rd Nest control only a damper in the ductwork or does it wire back to the air handler?

Did it do a software update when you first installed it? If so try going to settings and factory rest the Nest then install in again go thu all the setup steps again see if it clears the error code.

[wjp039]

Thank you Houptee, the 3rd Nest goes back to an air handler.

I tried the factor reset after your advise, reinstalled, same issue/error code.