During the servicing of a residential air conditioning system, what should be checked first if there is no airflow from the vents?

When diagnosing a situation where there is no airflow from the vents in a residential air conditioning system, the blower motor operation should be the first aspect to check. The blower motor is responsible for circulating air through the ductwork and into the living spaces. If the blower motor is not functioning properly—whether it has power issues, is obstructed, or has failed—then air will not move through the system, leading to the absence of airflow from the vents.

Addressing the blower motor first is critical because even if there are no issues with the refrigerant levels, ductwork, or thermostat settings, a malfunctioning blower motor will prevent conditioned air from being delivered effectively. Once the blower motor is confirmed to be operational, then troubleshooting can proceed to check other components such as refrigerant levels, ductwork for obstructions, and thermostat settings, as these may also impact the system's overall performance.