2820 S. Lamar Blvd. Austin, TX 78704
Setpoint Services responded to a commercial air conditioning service call at a 7-Eleven in Austin, Texas after the customer reported the Carrier rooftop HVAC unit was no longer cooling properly. Upon arrival, the indoor space temperature measured approximately 81°F, indicating inadequate cooling performance.
A complete diagnostic inspection revealed multiple airflow and maintenance issues contributing to the failure. The condenser coil was heavily impacted with dirt and debris, significantly restricting heat transfer. The evaporator coil was completely frozen due to poor airflow caused by an extremely loose blower belt. Additional inspection found the blower wheel heavily contaminated with dirt, the condensate drain pan and drain line filled with debris, and severely restricted non-OEM air filters reducing system airflow.
The blower belt was adjusted to restore proper tension, and the customer was advised to allow the evaporator coil to fully thaw before cleaning could begin. After completing another scheduled service call, our technician returned to perform the approved repairs.
During disassembly of the blower section, an additional mechanical failure was discovered that could not be identified while the evaporator was frozen. The blower wheel (squirrel cage) had become disconnected from the blower assembly, preventing the unit from being safely returned to service. An aftermarket breaker and sensor assembly connected to the incoming line voltage was also observed and documented for future evaluation.
Setpoint Services removed and disposed of the non-OEM air filters, thoroughly cleaned the evaporator coil, cleaned the heavily restricted condenser coil, cleaned the blower wheel and blower housing, cleaned the condensate drain pan, and cleared the condensate drain line to restore proper drainage. Due to the failed blower wheel assembly, the rooftop unit could not be fully reassembled or operationally tested.
A repair quote was provided to repair or replace the blower assembly before final startup and performance verification. Commercial HVAC preventive maintenance, including routine coil cleaning, belt inspections, drain cleaning, and filter replacement, is recommended to improve efficiency, prevent evaporator freeze-ups, and extend the life of rooftop air conditioning equipment.
