Read Any HVAC Wiring Diagram. Fix It Fast.
The field reference every HVAC tech needs — from ladder diagrams to low-voltage control boards.
Instant download. Works on any device. No subscription.
Most wiring callbacks happen because the tech traced the wrong leg. This guide teaches you to read the diagram before you touch the board — so you diagnose right the first time.
Every Diagram Type. Every Circuit Path.
Complete Ladder Diagram Library
Every major residential and commercial diagram type — annotated, organized by equipment class, and built for the tech who needs answers on site.
- Residential furnace & air handler diagrams
- Heat pump reversing valve & defrost wiring
- Commercial RTU & split-system controls
- Low-voltage thermostat wiring (2-wire through 10-wire)
Control Board Trace Guide
Step-by-step methods for tracing fault signals on modern control boards — without guessing which terminal is which.
ChatGPT Prompt Templates
Prompts for interpreting unfamiliar diagrams, tracing wiring sequences, and explaining circuit logic to customers.
Common Fault Wiring Patterns
The wiring mistakes that cause the most callbacks — and how to spot them on the diagram before they come back to bite you.
Instant Download
PDF format, optimized for phone and tablet — pull it up at the disconnect panel when you need it.
Built for the Tech Who Needs to Read It on the Job
The Apprentice
You can install equipment, but tracing a multi-stage heat pump diagram still takes you twice as long as it should. This fixes that.
The Service Tech
You get called back on wiring jobs more than you'd like. This teaches you to read the full ladder before touching anything.
The Lead Tech
Training your apprentices takes longer when they can't read diagrams. Give them a system.
From Techs Who Stopped Guessing on Wiring Calls
“I used to photograph the wiring and compare wire by wire. This guide gave me a system. I traced a faulty board in 12 minutes on a 95-degree call.”
Brandon K.
Service Tech, Phoenix AZ
“The heat pump reversing valve section alone is worth the price. Finally understand why that thing does what it does.”
Jason M.
Service Tech, Dallas TX
“Showed this to my apprentice on day one. He's reading diagrams on his own by week two. Didn't expect that.”
Miguel R.
Lead Tech, Riverside CA
Stop Guessing. Start Tracing.
The wiring guide every tech should have had on day one.