Not articles. Not theory. Checklists, charts, and guides built to be used on the job — fast, accurate, and always within reach.
Step-by-step diagnostic flow for residential and light commercial systems not producing cooling. Built to work through a fault systematically without missing a step.
Open Checklist →Full pressure-temperature chart for R-410A including liquid and vapor pressures, superheat targets, and subcooling targets. The chart you actually need on the job.
Open Chart →Every tool worth owning at every stage of your career. Tiered by experience level so you know exactly what to invest in next — and what can wait.
Open Guide →Step-by-step gas furnace diagnostic flow for no heat calls.
Full pressure-temperature reference for legacy R-22 systems still in the field.
Which refrigerants replace which, and what changes when you swap them.
What to check when a previous repair didn't hold. Systematic callback diagnosis.
Target ranges by system type, application, and ambient conditions.
Parts every tech should carry on their truck to avoid same-day return trips.