T3000 recently installed. I have one Red wire that is attached to “RC”. The User Guide says when wiring the thermostat, “If you have R, connect it to RH”.
Does the wiring need to be changed?
To better assist, can you submit a picture of the wiring?
I don’t have a picture of the wiring to submit because I already switched the one Red wire from “RC” to “RH”. The other connections remain the same: Blue to “C”; White to “W”; Yellow to “Y”; and Green to “G”. I kept on getting a recurring System Protect message with Red to “RC” and system would not activate at all or only come on for a couple of minutes before shutting down. After moving the Red to “RH” as the User Manual states, the system is functioning fine and no more System Protect messages. This is different approach than an answer to another question posed in the Support Forum where it was said that the workaround for continual System Protect messages was to install an Isolation Relay. Why would this easy fix work as opposed to the Isolation Relay option?
A problem may have more than one possible cause.
Assuming wiring is set up correctly, follow the support thread suggestions you referenced.
If wiring is not installed per the manual, please be sure that is done first.
Any change in wiring can have an impact on electrical characteristics, and the sensitivity of the thermostat’s digital relays is extremely high to these variations.