Most HVAC Systems Don’t Fail. They Get Failed.By the service report that said running well without running the acid test. By the jumper wire on the communicating inverter board. By the three refrigerant additions to a TXV that was stuck closed. The failed part is almost never the root cause. It’s the evidence. This book teaches you to find the murder weapon before you order the part.
20 Real Cases. 20 Murder Weapons.Dead on Arrival contains 20 real HVAC failure cases written as forensic investigations — compressors, TXVs, ductwork, electrical, heat pumps, condensers, A2L refrigerant systems, and multi-fault advanced scenarios. Every case follows a nine-part structure: the dispatch call, the scene, the evidence, the wrong diagnosis and exactly why it’s wrong, the murder weapon, the root cause, the repair done right, what happens without the full repair, and the lesson. No textbook scenarios. The actual calls — the ones that don’t follow the manual.
What’s InsideCases 1–3: Compressor failures — acid contamination, line set errors, flooded starts, and the crankcase heater nobody checkedCases 4–6: TXV and A2L metering — why high superheat isn’t always a charge problem, and why R-454B superheat calculation is differentCases 7–9: Airflow and ductwork — the crushed flex duct, the MERV killer, and the return grille that destroyed four compressorsCases 10–12: Electrical — ghost voltage, the board that wasn’t bad, and the inverter system that got jumped outCases 13–15: Heat pumps — reversing valve, defrost sensor, balance pointCases 16–20: Condensers, multi-fault sequencing, intermittent faults, and the new install that was wrong before the first startupField Reference Tools IncludedRoot Cause Failure Index — organized by symptom, not by componentPattern Summary Table — photograph it and keep it on your phonePre-Repair Checklist — five questions before any part gets orderedField benchmark tables for every case categoryWritten by a Field Engineer Who’s Done the WorkWritten by JD R. Lawson, a Licensed Mechanical Engineer with 25 years of HVAC design and field experience across the Philippines, Japan, and the United States. — the third book in The Forensic Technician series. Book 1, Why HVAC Systems Fail (ASIN: B084DQSDMC), and Book 2, HVAC Troubleshooting for the Modern Technician (ASIN: B0GXCRC83W) are available on Amazon
If you’ve ever written ‘unknown cause’ on a service report, this book is the answer to that report.
