At Fast Affordable Air, we recently serviced a rooftop Rheem Classic Series package HVAC system in the Las Vegas area. The customer reported poor cooling performance during the early afternoon hours, prompting a full system checkup.
Initial Inspection
Upon arrival, our technician conducted a visual inspection of the rooftop-mounted central air conditioning unit. This Rheem model provides both heating and cooling, all housed in a single weather-resistant package.
We verified that the power supply was secure and protective grilles were intact. The metal mesh around the base helps prevent wildlife from damaging refrigerant lines or chewing on control wiring.
Refrigerant Pressure Testing
Using a Yellow Jacket manifold gauge set, we connected to the high and low side service ports. The readings were:
- Low side (blue gauge): approximately 115 PSI
- High side (red gauge): approximately 290 PSI
These readings are within range for R-410A under typical outdoor conditions in Clark County, though we accounted for ambient rooftop temperatures nearing 90°F.
Electrical Testing
We used a Fieldpiece SC260 clamp meter to check microfarads (µF) across the run capacitor terminals. The measurement returned a reading of 5.92 µF, slightly below the expected rating. This suggests the capacitor is aging and may cause performance drops under load.
Note: A capacitor stores electrical energy and helps motors run efficiently. A failing capacitor may result in fan motors starting slowly or compressors struggling to engage.
Internal System Check
We opened the service panel and inspected the control board, fan relay, transformer, and wiring harness. All components were clean and free of burn marks or corrosion. The blower motor was tested and rotated freely, showing no signs of seizing or overheating.
The gas section of the unit was also visually inspected for signs of wear, rust, or possible leaks in the heat exchanger area. No abnormalities were found.
Observations and Adjustments
- We confirmed the refrigerant levels were adequate.
- The capacitor, while still operational, was logged for future replacement due to low µF tolerance.
- Coil surfaces appeared dusty but not clogged. We advised the homeowner to schedule a cleaning before the peak summer heat arrives.
Why It Matters
Maintaining proper refrigerant pressures and functioning capacitors ensures that the central air conditioner operates at peak efficiency. Even a few microfarads off on a capacitor can result in increased energy bills and reduce cooling performance. This is especially important in Las Vegas, where HVAC systems must keep up with intense summer heat.
If you’re experiencing uneven cooling or suspect your AC unit isn’t performing as it should, a full system diagnostic—like the one shown here—can pinpoint hidden issues before they become costly breakdowns.
Visit our AC Repair page to learn more about how we troubleshoot and restore comfort across Las Vegas, Henderson, and North Las Vegas.
