Customers heat on the first floor main zone is constantly running and not heating: * at arrival, the power is off to the system * Return power to the system and immediately the fan turns on and the system is showing an E3 error code * I found the limit switch roll out on right hand side tripped and reset system * the furnace fires normally * stop the call for heating at the ecobee thermostat but the furnace does not shut down * confirm that there is 24 volts between C and G and C and W at the furnace control board when ecobee thermostat is not calling for heat * when the W wire is removed the heat shuts down * when the G wire is removed the fan shuts down * check power between C and G and C and W at control board- no power * check power between C and G and C and W on thermostat wires- -24 volts * BAD THERMOSTAT- show customer all findings The customer wants to replace their existing ecobee thermostat with another ecobee thermostat that they will be providing. Installed a temporary