Theory and troubleshooting using short modules packed with images to make learning quick and easy.
Take any chance you have to skip connecting refrigerant gauges to a system. Each time you attach your gauges, you remove a small amount of refrigerant from the system through your hoses. The longer the hoses, the more charge that’s lost. After a few times of doing this, you might end up chasing a leak that doesn’t even exist.
If you want to know what is actually happening inside a refrigeration system, you have to look past the pressures. Gauges are a great start, but they only tell half the story. To truly diagnose a system, you need to understand the relationship between temperature and pressure. Superheat and subcooling are the vital signs of any HVAC unit. Whether you are dealing with a residential split system or a commercial chiller, these two numbers will tell you if the system is healthy, starving, or drowning.
The reversing valve is the heart of a heat pump’s ability to provide year-round comfort. It is the component responsible for seasonal switching, physically redirecting refrigerant flow to turn an air conditioner into a heater. For many technicians, however, the reversing valve is a source of frustration. It is often misdiagnosed and condemned prematurely when the real issue lies in the electrical system or the refrigerant charge. Understanding exactly how these valves function is the first step toward faster, more accurate service calls.