Fast Affordable Air recently serviced an older rooftop package HVAC system in the Las Vegas area. A package unit is an all-in-one Heating and Cooling system. The compressor, coils, blower, electrical controls, and other important parts are housed inside one large cabinet on the roof.
The property was having trouble getting steady Cooling from the system. During the inspection, our technician found two areas that needed attention. The air-side coil had a heavy layer of dirt and debris, and the reversing-valve control area needed to be checked closely.
These problems may look small at first. However, restricted airflow and a valve that does not switch correctly can make a central AC run for a long time without making the building comfortable.
Inspecting the Dirty Air-Side Coil
The first photo shows a coil surface covered with thick dirt. The thin metal fins should have open spaces between them so air can pass through. In this case, much of that open space was blocked.
An HVAC coil is made from metal tubing and many thin fins. Air travels across the fins so heat can move into or out of the refrigerant. Refrigerant is the special fluid that carries heat through an Air Conditioner or heat pump.
Dirt on a coil acts like a heavy blanket. The blower may still be running, but it has to work much harder to move air. Rooms may feel warm, airflow from the vents may become weak, and the Cooling system may stay on longer than normal.
The dirty air-side surface was cleaned as part of the service. Removing the buildup helps air move through the central Air Conditioning system more freely. It also helps protect the blower motor and compressor from the extra strain caused by poor airflow.
Opening the Rooftop Package Unit
The next photos show the package unit installed above a shingle roof. Before opening the cabinet, power to the equipment must be turned off. Rooftop HVAC equipment contains high-voltage electrical parts, moving fan blades, and pressurized refrigerant.
After the access panels were removed, the technician inspected the refrigerant tubing, electrical wires, indoor coil, outdoor coil, and cabinet condition. The roof stand and duct transition were also checked.
A duct transition is the metal section that connects the rooftop Air Conditioner to the building’s ductwork. It must remain secure and properly sealed. Open gaps can allow hot roof air, dust, or moisture to enter the system.
Rooftop equipment receives direct sunlight for much of the day. In the Las Vegas Valley, that heat can be hard on wires, insulation, motors, and metal panels. Careful inspection is an important part of professional AC repair in Las Vegas.
Checking the Reversing Valve and Solenoid
Several close-up photos show the reversing valve inside the unit. A reversing valve is a part used in a heat pump. It changes the direction in which refrigerant travels so the system can switch between heating and cooling.
Attached to the valve is a small electrical part called a solenoid coil. The solenoid acts like an electric switch. When it receives power, it helps move the reversing valve into the correct position.
The technician inspected the solenoid, its blue control wires, the valve body, and the nearby copper tubing. The wiring had to be checked for loose connections, damaged insulation, or signs of overheating.
When a reversing valve does not shift correctly, a heat pump may become stuck in one operating mode. For example, the thermostat may call for Cooling while the refrigerant continues moving in the wrong direction. The fan can blow, but the air may not become cold.
This is why the valve cannot be judged by appearance alone. A trained technician must check whether the solenoid receives the correct voltage and whether the valve responds when the system changes modes. More information about this type of equipment is available on the heat pump repair and service page.
Inspecting the Outdoor Coil and Refrigerant Tubing
The outdoor coil wraps around several sides of the package unit. This coil releases heat while the system is running in Cooling mode. Its fins need open space around them so outdoor air can carry the heat away.
The technician looked for flattened fins, heavy dirt, oil marks, damaged tubing, and blocked airflow. An oil mark can sometimes point toward a refrigerant leak because refrigerant oil travels through the tubing with the refrigerant.
The copper lines around the reversing valve were also inspected for rubbing and vibration damage. Copper tubing can slowly wear through when it touches another pipe or a sharp cabinet edge for a long period.
Reassembling and Testing the Cooling System
After the airflow area, valve controls, wiring, and coils were serviced, the access panels were placed back in position. Keeping the panels installed correctly is important. The blower depends on the cabinet being closed so it can pull and push air through the correct path.
The system was then operated through a Cooling cycle. The technician listened for unusual sounds, checked the fan operation, watched the refrigerant components, and confirmed that the unit was responding to the thermostat.
Regular AC maintenance can help find dirty coils, loose wires, worn controls, and airflow restrictions before they cause a complete breakdown.
Benefits of the Air Conditioning Service
- Cleaner airflow through the central Air Conditioner
- Less strain on the blower motor and compressor
- Better movement of cooled air through the rooms
- More reliable switching between heating and cooling modes
- Less wasted electricity from long operating cycles
- Lower risk of coil freezing caused by poor airflow
- Improved indoor comfort during hot Clark County weather
- Early detection of damaged wires, tubing, and rooftop connections
