Mike PleziaInside service technician, Clark Associates · Commercial Equipment, HVAC, and Refrigeration professional

A Five-Step Way to Diagnose Anything

6 Sept 2026 · 2 min

Watch on YouTube

1:35

In this concise instructional video, an experienced HVACR technician outlines a repeatable five‑step troubleshooting loop designed for new technicians. The loop begins with identifying the symptom (what the equipment is doing or not doing), then verifying that symptom by safely observing the system in operation. Next, the technician isolates the cause by breaking the system into smaller sections and testing for power, call for operation, airflow, or safety conditions to pinpoint the failed component, wiring, setting, or condition. The fourth step is to make the repair, followed by a crucial fifth step: confirming the fix by running the equipment through a normal cycle to ensure the original symptom is gone and no new issues were introduced. The speaker emphasizes that consistently applying this loop makes new technicians appear calm, careful, and professional, and encourages sharing the method with others.

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Hey! Are you new to the trades? Here's something you may not know about diagnosing anything in HVACR. Good troubleshooting is not a talent trick. It is a repeatable, 5-step loop. First, identify the symptom. What is the equipment doing or not doing? No cooling is a complaint. A blower that runs while the outdoor unit stays off? Is a useful symptom. Second, verify the symptom yourself. Run the system safely and see it happen. Verify before you repair. That keeps you from chasing a customer description that has changed since they called. Third, isolate the cause. Divide the system into smaller sections and test what should be present: power, A call for operation, airflow, or a safety condition. Find the failed part, wire, setting, or condition— not just the thing that looks suspicious. Fourth, make the repair. Then comes the step new techs sometimes skip: confirm the fix. Put the equipment through a normal cycle, check the original symptom is gone, and make sure your repair did not create another problem. Use this same loop on every call. It makes a new technician look calm, careful, and professional. Now that you know, you can help someone else know.