Our team at Fast Affordable Air recently tackled a full diagnostic and repair project on a central air conditioning system that had lost cooling power in a Las Vegas attic installation. The job involved checking refrigerant pressures, evaluating indoor and outdoor components, and replacing a failed capacitor that was keeping the system from running efficiently.
Indoor Furnace Diagnostics
We began our inspection in the attic, where the Rheem Criterion gas furnace was mounted. The air handler and gas heat components were connected to flexible foil-insulated ductwork. Visually, everything looked solid — the cabinet was sealed, the flue pipe was intact, and the intake and exhaust lines were correctly routed. However, further testing showed the system wasn’t operating at full potential.
Voltage Check
Using a Fieldpiece SC260 multimeter, we verified 168.1 volts AC at the outdoor unit’s electrical contacts. This voltage reading was critical to ensure the outdoor condenser was receiving proper power. Anything significantly under 208–240V could cause malfunction or damage to components like the compressor and fan motor.
Refrigerant Pressure Testing
We connected Yellow Jacket manifold gauges to assess system pressures. The red (high side) and blue (low side) dials showed refrigerant levels undercharged, which can indicate a slow leak, recent refrigerant loss, or insufficient charge during prior servicing. When refrigerant levels are low, cooling performance drops and components have to work harder, shortening their lifespan.
Capacitor Replacement
The real culprit? A failed run capacitor. The round capacitor located in the outdoor unit was tested and found to be faulty — it wasn’t providing the proper boost to the condenser fan motor or compressor. We replaced it with a new capacitor from PROParts HVAC Parts & Supplies, which restored the motor startup and stabilized operation.
Airflow and Venting Check
Back in the attic, we checked the metal duct plenum and foil flex duct connections for air leaks. All connections were sealed properly and routed to ensure efficient air distribution. We also inspected the vent pipe (flue) attached to the gas furnace for safe exhaust routing out of the attic.
System Benefits After Repair
- Improved Cooling: With the capacitor replaced and refrigerant levels adjusted, the central AC began cooling much more efficiently.
- Reduced Energy Bills: A fully charged and properly powered AC uses less electricity to cool the same space.
- Longer Equipment Life: The motor and compressor now run without overloading or struggling to start.
- Safe Heating: The Rheem gas furnace’s flue system remains secure, reducing any risk of combustion gas backdraft.
Every component, from the capacitor to the ductwork, plays a role in overall system performance. Regular maintenance and quick repairs like this ensure comfort year-round for homeowners in Las Vegas, Henderson, and nearby communities.
Learn more about how we service heating systems and air conditioners at Fast Affordable Air.
