Air Conditioning Repair on a Rooftop Package Unit, From Old Cabinet to a New Rooftop Setup

On this job, our technician worked on a rooftop HVAC system that handles both AC and heating in one big metal box. A rooftop package unit is common in desert neighborhoods because it keeps the equipment outside, saves yard space, and connects straight down into the home’s ductwork.

The photos show a full rooftop service flow, starting with an older unit and roof curb area, then moving into setup, tool staging, and final install photos of a newer Rheem rooftop unit sitting on a sealed roof base. The goal is simple for the homeowner. Stronger central cooling, safer operation, and fewer surprise breakdowns in the heat.

Step 1) Rooftop safety setup and work area control

Before touching any Air Conditioner parts, we make the roof work area safe. Rooftops can be slippery, hot, and steep. In the photos, you can see a large umbrella being used to create shade over the unit area. Shade helps protect tools and helps the technician stay focused when the sun is intense.

Simple definition: A “work zone” is the safe spot where we keep tools, parts, and hoses so nothing slides or falls.

Step 2) Confirm the system type and inspect the rooftop package unit

Next we confirm what kind of Heating and Cooling system we are working on. A package unit is different from a split system. With a split system, you have an outdoor condenser on the ground and an indoor air handler in the attic or closet. With a rooftop package unit, the cooling coil, blower, and outdoor coil are all inside the rooftop cabinet.

We inspect the cabinet, the panels, and the connection points. This includes looking at the supply and return duct openings, checking for loose screws or sharp metal, and making sure the roof curb area is stable.

Step 3) Tool staging and refrigerant diagnostics

Several photos show a manifold gauge set placed near the unit. Gauges help a technician check refrigerant pressures. Think of refrigerant like the “blood” that carries heat out of the home. If refrigerant levels are wrong, cooling suffers.

Simple definition: A “manifold gauge set” is a tool with hoses and dials that tells us what the refrigerant is doing inside the system. Example: If pressures are too low, the AC may not cool well.

The rooftop unit label in the pictures indicates an R-410A refrigerant system. That matters because the correct tools and procedures must match the refrigerant type.

Step 4) Roof curb and flashing review, stop air leaks and water leaks

One of the most important parts of a rooftop job is not only the unit itself, but also what the unit sits on. The roof curb is the raised “frame” that the rooftop package unit mounts to. Around that curb, you can see sealant and coating that helps block water and air leaks.

• Why sealing matters for comfort: Air leaks at the curb can let cooled air escape into the attic or roof cavity.
• Why sealing matters for the roof: Water intrusion can rot wood and damage ceilings.
• Why sealing matters for efficiency: If air escapes, the AC runs longer and energy costs go up.

Step 5) Electrical and disconnect check

Rooftop units have high voltage power feeding the cabinet. The photos show the electrical pathway and a disconnect area. We check that wiring is properly protected, secured, and routed so it does not rub on sharp metal edges.

Simple definition: A “disconnect” is a safety switch that shuts off power so a technician can work on the system safely.

Step 6) Gas line and piping awareness

Many rooftop packages in Las Vegas are gas/electric units. That means the same cabinet can do heating (gas) and cooling (refrigerant). The photos show rooftop piping, including a vertical pipe coming through the roof area near the unit. When gas is present, we verify safe routing and stable supports.

Any time a roof penetration exists, we also look at the seal around it because roof openings are common leak points.

Step 7) Final placement and finished rooftop unit install

The later photos show a clean finished setup with a newer Rheem Classic rooftop package unit installed and sitting squarely on its base. The cabinet panels are in place, the top fan grill is secure, and the perimeter sealant around the curb area looks fresh. This is what we want to see after a rooftop AC repair or replacement style project.

Common questions people ask about rooftop package units

Why does a package unit sit on the roof?

It saves yard space and keeps noisy equipment outside. It also keeps the Heating and Cooling system in one spot, which can make service access simpler.

What is “airflow” and why does it matter?

Airflow is how much air the blower can push through the ducts. If airflow is weak, the home can feel warm, even if the AC is running. Proper setup and sealed connections help the system deliver cool air to every room.

What is a roof curb?

The roof curb is the raised frame under the rooftop unit. It supports the weight, lines up the ducts, and helps keep water out of the roof opening.

Helpful service links from Fast Affordable Air

• HVAC Services (Las Vegas Valley)
• Rooftop package unit repair example (coil, airflow, connection checks)
• 10 Year Repair Warranty details
• Contact page and service area info

Extra high-value reference

The U.S. Department of Energy shares simple tips on maintenance that can help systems cool better and run more efficiently, especially in hot climates. Energy Saver guide on maintaining your air conditioner