Heating, Ventilation, and Air Conditioning (HVAC) Electrical Practice Test 2025 - Free HVAC Practice Questions and Study Guide

When the thermostat is set to ON and the blower does not operate, it is a clear indication that there may be a problem with the blower motor. The blower motor is responsible for circulating air through the HVAC system. If the thermostat calls for operation but the blower fails to start, it suggests a malfunction within the motor itself, the associated wiring, or the control system.

In contrast, conditions such as the indoor unit leaking water could indicate issues with drainage or condensation but do not directly reflect on the functionality of the blower motor. Similarly, if the thermostat is functioning properly, that merely confirms the communication between the thermostat and the system, not necessarily the operational status of the blower motor. Additionally, the outdoor unit cycling correctly pertains to the heat exchange process and does not provide insights into the indoor blower's performance.

Thus, the situation where the thermostat is set to ON and the blower fails to operate is the most direct indicator of a potential issue with the blower motor.