HVAC worker cheat sheets built for field decisions, not content fluff
These are original quick-reference sheets for techs and installers. Use them for faster diagnosis, safer handoffs, and cleaner callbacks. Always follow manufacturer data, lockout/tagout procedure, and local code when the cheat sheet and the equipment disagree.
Airflow references your crew can use immediately
Airflow, CFM, and Static Pressure Quick Check
Use this when you have hot and cold rooms, noisy returns, frozen coils, or a unit that feels starved for air.
Cooling Delta-T and Split Temperature Sanity Check
A quick field reference for using return-to-supply temperature difference without over-reading one number.
Electrical references your crew can use immediately
24V Control Circuit Troubleshooting Ladder
Use this for no-cool, no-heat, or no-fan calls when the low-voltage circuit is the likely control failure point.
Capacitor and Contactor Field Checks
A fast reference for the two outdoor-unit failures you can lose a day on if you skip the basics.
Refrigeration references your crew can use immediately
Heating references your crew can use immediately
Heat Pump Defrost Troubleshooting Cheat Sheet
A field-side reference for when the outdoor unit is icing, short-defrosting, or never defrosting at all.
Gas Furnace Sequence of Operation and Safeties
A quick ladder for no-heat calls so you can prove exactly where the sequence breaks.