An autodiscovery system for configuration information about an HVAC system being provided to a controller or thermostat. Configurations or parameters may be autodiscovered from communicating equipment. Also, this equipment may be manually selected and set without affecting the autodiscovery status of the remaining equipment. There may also be non-communicating equipment that does not provide information to the thermostat. However, the thermostat may control the non-communicating equipment via an equipment interface module.