HVAC Ladder: Wiring Diagrams

Draw professional HVAC ladder diagrams right on your phone — built by a working HVAC tech, for the techs in the trade. HVAC Ladder is a fast, finger-first editor for electrical ladder diagrams and wiring schematics. Sketch a control circuit in the truck, document a repair before you leave the roof, or teach a class how a heat pump actually sequences — then export a clean, print-ready diagram. DRAW IN SECONDS • Hold and drag symbols straight onto numbered rungs • Real ladder layout: L1/L2 rails, an L3 leg for three-phase loads, parallel branches • The diagram scales to your screen — phone, tablet, portrait or landscape • Undo, autosave, and crash recovery protect every change A REAL HVAC SYMBOL LIBRARY • Contacts, push buttons, and relays • Pressure switches, thermostats, flow, float, and limit switches • Motors, compressors, heat elements, transformers, capacitors, start relays • Multi-terminal thermostat block (R, G, Y, W, C and more) and a Hand-Off-Auto selector block • Tap any symbol to see its full name and plain-English meaning — great for apprentices EXPORT & SHARE • Black-and-white PNG and vector PDF exports with a title block: project, equipment, name, and date • Diagrams print clean — black on paper, like a real schematic • Share the editable diagram file itself; it opens on any device running HVAC Ladder BUILT FOR THE FIELD • 100% offline — no account, no sign-in, no ads • We collect nothing. Your diagrams stay on your device, period • Dark mode for attics and equipment rooms, light mode for daylight TEACHING & LEARNING • Guided tour walks you through wiring a fan control with a transformer • Built-in symbol glossary and a full illustrated manual • Ready-made example circuits: heat pump with defrost, walk-in cooler, air compressor, start-stop with indicator light • Instructors: sketch a circuit live in class; students: label every component as you learn it WHO IT'S FOR HVAC technicians documenting control wiring in the field. Apprentices learning to read a ladder diagram. Instructors teaching electrical schematics. Facility and refrigeration techs who need a wiring diagram that matches what's actually in the panel. Made by HVAC Mobile — a working technician who wanted a ladder diagram app that speaks the trade's language. Questions or ideas? There's a direct email link inside the app; real feedback from real techs shapes every update.