Over 800 field-ready tech tips, organized so you can find what you need from the truck. Pick a category, tap a tip.
Prefer to browse every tip in one big list? View the classic alphabetical Tech Tips page.
Start Here & Fundamentals
Start Here
New to the trade? Work through these tips in order. They cover the fundamentals every tech needs before anything else makes sense.
Fundamentals & Science
The physics under the hood: heat transfer, gas laws, pressure, and the science behind why systems do what they do.
Refrigerant-Side
Refrigeration Circuit, Charging & Diagnosis
Superheat, subcooling, delta T, and reading system vitals. These are the core measurements and what they tell you.
Metering Devices & Valves
TXVs, EEVs, pistons, and every valve in the circuit, including how they work, how they fail, and how to diagnose them.
Compressors
The heart of the system. Operation, protection, failure diagnosis, and replacement done right.
Brazing, Vacuum & Refrigerant Handling
The hands-on craft of brazing, flaring, pressure testing, evacuation, and recovery best practices.
Refrigerants, Oils & Regulations
A2Ls, retrofits, refrigerant properties, oils, and staying on the right side of the EPA.
Electrical & Controls
Electrical Fundamentals & Troubleshooting
Volts, ohms, amps, and circuits, with safe measurement and confident electrical diagnosis.
Motors, Capacitors & Starting Components
ECMs to PSCs, capacitors, contactors, and everything that spins or helps something start spinning.
Controls, Thermostats & Boards
Low-voltage logic: thermostats, control boards, safeties, sensors, and control wiring.
Air-Side & Comfort
Airflow, Ducts & Static Pressure
Moving air properly with static pressure, duct design and repair, blowers, and airflow measurement.
Psychrometrics, Humidity & IAQ
Moisture, humidity, ventilation, and filtration. Delivering air that is actually healthy and comfortable.
Building Science & Load Calculation
The house as a system: Manual J, equipment sizing, envelopes, and why design starts with the building.
Condensate & Drains
Small pipes, big callbacks. Drain design, traps, switches, and cleaning.
Systems & Applications
Heat Pumps, Ductless & Inverter Systems
Heat pumps, mini-splits, VRF, and variable-speed tech, including the quirks, the wiring, and the diagnosis.
Gas Heating & Hydronics
Furnaces, combustion, venting, boilers, and hydronic heat.
Commercial HVAC & Refrigeration
RTUs, chillers, economizers, ice machines, racks, and market refrigeration.
The Craft
Tools & Instruments
Choosing, using, and trusting your instruments, from multimeters to micron gauges.
Safety
Going home in one piece. Electrical, lifting, respiratory, and jobsite safety.
Installation, Maintenance & Service Practices
Doing the work right, with install best practices, maintenance procedures, and callback prevention.
Diagnosis & Troubleshooting Method
How to think like a diagnostician: process, mindset, and avoiding tunnel vision.
Career, Business & Soft Skills
The human side of the trade. Growth, communication, business sense, and hard-won wisdom.
