Every course below is included free with the Apprentice tier — no per-course fees, no upsells. Start with the certification you need today; the AI Sensei drills you against real exam patterns until you're ready to sit it.
Type I, II, III, and Universal. Required to handle refrigerants under EPA 40 CFR Part 82. Approx. 20 hours of focused prep.
A2L safety classification, leak detection, equipment compatibility, field-installation procedures. ~8 hours. Critical for the R-410A → R-454B transition.
End-to-end on R-454B — the A2L replacing R-410A in 2026 new equipment. Covers code changes, equipment compatibility, and field service procedures. ~6 hours.
Air Conditioning, Heat Pump, Gas Heating, Light Commercial, HVAC Efficiency Analyst tracks. Unlimited Sensei drilling, then sit the proctored exam.
ATH's signature program — train across all four trades with one account. Each trade has its own dedicated AI Sensei (HVACR Sensei live, Plumbing Sensei live, Electrical Sensei beta, Welding Sensei Q3 2026). Stack credentials over time; upgrade to Journeyman when you're managing your own apprentices.