During a maintenance call, after discussing performance with the equipment owner, what should the technician set the FAN switch to?

Setting the FAN switch to "ON" during a maintenance call allows the technician to check that the blower is continuously running, which is crucial for assessing the system's airflow and performance. When the FAN switch is in the "ON" position, the fan operates regardless of whether the heating or cooling system is activated, providing a clear view of the blower's functionality.

This choice is essential for determining if the blower is working properly, as it should circulate air throughout the system. If the blower does not operate in this position, it indicates a potential issue with the fan motor, relay, or associated wiring that needs to be addressed. Continuous operation also helps the technician to identify any unusual noises or vibrations that could signal other mechanical problems.

In contrast, options that involve measuring voltage, such as from the R to the G terminal or R to W1 terminal, do not provide immediate feedback on the blower's operational status. The focus should first be on ensuring the equipment performs correctly before delving into electrical measurements. Additionally, checking system performance in the "AUTO" position might not provide a reliable assessment of the blower’s operation under normal conditions, as the fan may not run if the heating or cooling call is not active. Therefore, ensuring that the fan is actively