Diagnose it. Don't guess it.
Deterministic HVAC-R fault diagnosis for working field techs. Pressures in. Ranked faults out. With the reasoning, every time.
Most diagnostic apps guess. This one shows its work.
Three maybes and a shrug
Every other app throws three possible faults on the screen with no explanation and expects you to pick one. That's not a diagnosis — that's a coin flip with extra steps.
An AI that hallucinates parts
The new wave of "AI assistants" will confidently tell you to swap a $400 TXV when the real problem is a clogged filter-drier. Made-up reasoning is worse than no reasoning.
PT charts in a glovebox, math in your head
The tools that don't guess instead make you do everything by hand. Lookup. Interpolate. Subtract. Re-check. On a 100°F rooftop with a customer waiting.
The Diagnostic Pro difference
Deterministic, not probabilistic
A weighted scoring engine — not an LLM — ranks every fault on every call. Same inputs always give the same answer, and the reasoning is right there next to the score.
Pre-check gate before any reading
The app blocks the diagnosis until airflow, coil, blower, and stabilization are confirmed. Bad readings in, bad faults out. We won't let you.
Built around your hands
Glove-friendly tap targets. Industrial dark UI. Big numbers, no fluff. Works offline so basements and rooftops aren't a problem. Designed for the truck, not the office.
Five senses, in the right order
Before you read a single pressure, the app walks you through the checks a senior tech would do on instinct.
Pre-check gate
Before any pressure gets entered, the app walks you through visual inspection, airflow, coil cleanliness, filter, blower, and stabilization. Skip a step and the diagnosis button stays disabled. The cheap stuff hides expensive symptoms — this catches them first.
Live SH / SC engine
Six refrigerant libraries — R-410A, R-22, R-32, R-454B, R-134a, R-404A — with linear interpolation. Punch in your pressures and temps; superheat, subcooling, and saturation temps update live as you type. A2L refrigerants are flagged automatically.
Ranked faults, with the reasoning
A weighted engine ranks seven fault models — undercharge, overcharge, liquid line restriction, metering device restriction, airflow issue, non-condensables, normal operation — by confidence. Each ranking shows the indicators that produced it, so you can disagree with the engine and still leave the call right.
Symptom matrix & quick calcs
A printable, glove-friendly cheat sheet of every common fault signature on every refrigerant. Quick calcs for target superheat (TXV vs. fixed orifice), capacity, delta-T, and rule-of-thumb sanity checks. The reference card you wish was in the truck.
Plate camera & parts sourcing
Snap a photo of the data plate — the app reads model and serial, looks up specs, and surfaces matching parts across five major suppliers in one place. Get the right capacitor on the truck before you finish writing the invoice.
Service reports, customer-ready
Every diagnostic exports as a printable service report in plain language — what was checked, what was found, what was fixed. The kind of paper trail that defends the invoice and earns the next call.
Offline first
Basements. Rooftops. Equipment rooms. The whole engine runs without a signal — saved jobs and diagnostics sync the moment you're back in range. No bars, no excuses.
Every seat. Every feature. Every refrigerant.
No paywalled fault models. No "pro tier" for the math.
Honest pricing. Founder-tester deal.
The first 25 working techs to join the beta get the full app free for life. After that, it's $29 a month or $290 a year. No tiers, no seat math, no upsells.
Founder Beta
- Every feature, forever
- All future updates included
- Direct line to the founder
- Locked in for life of the company
Monthly
- Full diagnostic engine
- Offline mobile app
- All 6 refrigerant libraries
- Cancel anytime
Annual
- Everything in monthly
- Priority support
- Annual price locked
Frequently asked questions
Diagnose it. Don't guess it.
First 25 beta testers get every feature, every refrigerant, every update — free for life. After that, it's $29 a month. The deal goes away when the seats are gone.