On a recent service call, our team at Fast Affordable Air was called out to inspect a rooftop central air conditioner at a commercial property in Las Vegas. The building’s cooling performance had dropped significantly, and the maintenance team noticed water stains and unusual system noise.
The unit we serviced was a rooftop package system. This type of AC system combines both the cooling and heating components into one box, which is installed on top of the roof. They’re common for commercial buildings because they save space and are easier to access for service without disrupting indoor operations.
Inspection and Diagnostic Procedure
Upon arrival, we first examined the unit visually. Right away, we noticed signs of water runoff around the base — a clear sign that the condensate drainage line wasn’t working as it should. We also opened the side access panels to get a closer look at the internal components.
We checked the electrical disconnect box and wiring — all seemed intact. Then we tested the system’s blower motor, capacitor, and refrigerant charge levels. These are all core components that can cause cooling issues when they malfunction.
Drain Line & Water Damage Check
One key discovery was a blocked condensate line. Over time, dirt and algae can clog this pipe, which is supposed to carry water safely away from the unit. When it clogs, water backs up into the unit or spills onto the roof — which can lead to staining or even structural damage over time. This issue was clearly visible around the perimeter of the unit in multiple photos.
We cleaned the drain line and made sure it was sloped correctly to let gravity do its job. We also inspected the surrounding roofing membrane to confirm no lasting damage had occurred.
Refrigerant & Coil Inspection
After clearing the drain line, we moved on to check the condenser coil. This coil helps release the heat the system pulls from inside the building. When it’s dirty or clogged, efficiency plummets. In this case, the coil was dusty, so we gave it a rinse with coil cleaner and water.
Next, we connected our manifold gauge to check the refrigerant pressure. This system uses R-410A, a standard refrigerant in modern systems. The pressures were slightly low, suggesting a potential small leak or undercharge. We topped off the refrigerant and monitored the system to ensure no further loss occurred.
Electrical Tune-Up
With power off, we inspected the capacitor, contactor, and wire terminals. The capacitor — which stores energy and helps start the motors — was reading slightly below spec. We replaced it with a new matched component to ensure smoother start-ups and better energy efficiency.
We also reseated all electrical terminals and used a screwdriver to tighten any loose connections, helping prevent future electrical shorts or power drops.
Why Rooftop Units Need Routine Checks
Because they’re exposed to sun, wind, dust, and even birds, rooftop HVAC systems take a beating. Roof temperatures in Las Vegas can reach 150°F+ in summer. Components degrade quickly under those conditions.
Routine inspections like this one can prevent major system failures, protect the building’s roof, and ensure comfortable indoor air temperatures even during the hottest weeks of July and August. Proper drainage, clean coils, and the right refrigerant levels are all essential for peak performance.
Las Vegas AC Repair Experts
Our licensed HVAC technicians serve commercial and residential properties throughout Las Vegas, Henderson, North Las Vegas, and the surrounding Clark County areas. Whether you need a rooftop unit serviced or a complete system replacement, Fast Affordable Air has the tools and expertise to get the job done.
Want to learn more about how central air conditioners work or see more of our projects? Visit fastaffordableair.com for tips, service info, and expert HVAC help.
