We were recently called out to a home in Las Vegas to diagnose and repair a central air conditioning system located in the attic. The system is a horizontal gas furnace and coil configuration with flexible insulated ducts feeding multiple rooms throughout the home. It had not been cooling properly, and the homeowner noticed warm air was coming from the vents.
Initial Inspection: Verifying System Setup and Airflow
Our technician started by visually inspecting the full setup. As seen in the attic photo, the attic HVAC unit was mounted securely with properly routed return and supply ducting. The ducts were sealed and insulated, but we noted signs of dust and mild air leakage, especially near the plenum connections.
We followed the drain line piping as well and confirmed the presence of a primary and secondary drain line. These ensure that if condensation builds up, it can safely exit without leaking into the attic.
Electrical Testing at the Motor Assembly
Next, we accessed the blower assembly to test the motor and capacitor. Using a multimeter, we measured voltage across the terminals to verify the power delivery and capacitor performance. These tests help determine if the motor is running efficiently or if it’s overloaded.
In one of the close-up shots, you can see the technician carefully testing the terminals at the motor’s capacitor bracket. This part stores energy to help the motor start and run smoothly. A weak or failed capacitor can prevent the blower from running or cause short cycling.
Sealing and System Airtightness
We also took time to examine the refrigerant line connections entering the air handler. As seen in the image, the suction line was sealed with mastic and foil tape. Mastic is a thick adhesive used to prevent air leaks and protect from condensation. Although the connection was mostly intact, we reinforced a few areas that looked brittle or aged.
Sensor & Flame Inspection
We removed the burner cover to inspect the flame sensor and burners. A flame sensor ensures the burners ignite correctly and shuts off gas flow if no flame is detected. Over time, this sensor can get coated in residue. Cleaning or replacing it helps maintain safe operation.
The close-up photo reveals the sensor and igniter assembly were dusty, and we gently cleaned it with a fine abrasive pad before reassembling.
Static Pressure and Damper Adjustment
On the supply plenum, we noted a fresh air damper actuator. This component helps balance how much outside air mixes with the indoor return, improving air quality and efficiency. We ensured the damper opened and closed correctly and confirmed it was wired into the control board properly.
Final Steps and Summary
Once electrical tests were complete, the burners and sensor were cleaned, duct sealing reinforced, and the system cycled through heating and cooling modes. We monitored air temperature at multiple vents to confirm balanced distribution and improved airflow.
This project shows how small components—like sensors, capacitors, and seals—play a big role in how efficiently and safely a central heating and cooling system works. By taking a detailed approach, we made sure this home’s HVAC system runs cleaner, safer, and more efficiently going forward.
