RTU#4 found error code EB (incorrect thermostat input). Thermostat was programmed for heat pump and appeared to short out when it made a W call. Tech reprogrammed the thermostat from heat pump to AC and was only receiving 11volts to the unit from a W call. Tech replaced the thermostat face plate only due to having a stripped back plate on a “new out the box” Vision Pro thermostat and managed to get the system to operate heat. System #4 is a 2 stage straight AC and heat strip only unit. Wiring, Vision Pro thermostat face replaced, and reprogrammed the thermostat was well to its corresponding settings. RTU#4 is back heating. Install warranty.