Air Systems Cleaning Specialist (ASCS) Practice Exam

To determine if a residential thermostat is functioning properly, setting the thermostat to an extreme temperature and observing the unit's response is an effective method. This approach tests the thermostat's capability to initiate a call for heating or cooling by evaluating whether the HVAC system reacts appropriately after the temperature is set to a significantly high or low setting. If the thermostat is functioning correctly, you should see the heating or cooling system activate accordingly, indicating that the thermostat is communicating effectively with the HVAC system.

This method allows the technician to assess not only the thermostat operation but also ensures that the entire system is responsive to temperature changes dictated by the thermostat settings. Monitoring the system's response helps identify any potential issues, such as the thermostat being unresponsive or the HVAC equipment failing to operate when commanded by the thermostat.