A credential-gated, real-time diagnostic and repair assistant that lets a novice technician perform like a mid-to-senior tech — safely — on live service calls.
The Repair Copilot is the service-side companion to the Stage 1 survey tool. A technician dispatched to a trouble call opens the app on arrival, selects the equipment they're there to service, and is walked — in real time — from the customer's reported complaint, through verifying it, identifying the full system, diagnosing on actual measured readings, and into the hands-on repair and a confirming check that it works.
It is a service application, not an installation tool. It guides repair of existing equipment; it does not install or commission new systems (a separate future build).
The same diagnostic path adapts to the individual using it. Every technician has a profile — an experience level and a set of admin-granted credentials. The tool guides each person exactly as far as they are qualified, then stops and escalates.
Example, a "no cooling" call: a technician who is EPA 608 Type II but not yet cleared for line-voltage rewiring is guided all the way through airflow, power, capacitor, contactor, and refrigerant diagnosis. If the fault turns out to be burned line-voltage wiring, the tool stops him at that step — "this requires line-voltage clearance; here's everything you've confirmed, escalate to a qualified tech" — while a colleague whose profile clears it is guided straight through the repair. One intelligent path, different stopping points per person.
This is what turns a novice into an apparent mid-to-senior performer: the structure, the step-by-step "how," and the reasoning come from the tool; the work stays within what the person is genuinely qualified and safe to do.
Two layers plus an override flag, all admin-set. Gates govern what work is permitted; level governs how much hand-holding and override eligibility; the override flag clears specific conditional safety stops.
Use of a multimeter, screwdrivers, and diagnostic tools including temperature probes; visual competency; knowledge of system components; EPA 608 Type II (company minimum). Plus: measuring voltage/amperage anywhere, all 24V low-voltage control work, and like-for-like single-phase swaps of capacitor, contactor, and simple relays; gas-pressure readings and igniter / flame-sensor / thermocouple swaps; standard split-AC and forced-air furnace service.
| Code | Gate | Unlocks (beyond baseline) |
|---|---|---|
| EPA-U | EPA 608 Universal | All refrigerant types (baseline already covers Type II high-pressure work: recovery, evac, charging, leak repair on split AC & heat pumps). Universal adds low-pressure/chiller. Type I & III not modeled now. |
| E1 | Line-voltage (single-phase) | Repair/replace burned line-voltage wiring, whips, disconnects, hard-wired motor rewiring. |
| E2 | Three-phase (hands-on) | Hands-on work on 3-phase gear. Measurement/diagnosis on 3-phase is allowed for all techs — only modification is gated. |
| E3 | New circuit / branch wiring | Run a new circuit from the panel, extend branch wiring, new disconnects beyond like-for-like. |
| G1 | Gas valve / gas piping | Replace gas valve, work on gas connections/unions where a seal is broken (leak-test required). |
| G2 | Combustion & venting | Combustion analysis (CO/O₂), venting/draft sign-off, confirming a cracked heat exchanger. |
| HP | Heat pumps | Reversing valve, defrost, low-ambient, aux/emergency-heat logic, HP charging specifics. (Tech still services as a straight AC up to HP-specific parts.) |
| B1 | Hot-water / hydronic boilers | Circulators, expansion tanks, zone valves, aquastats, hydronic controls. |
| B2 | Steam boilers | Steam controls, low-water cutoffs, pressuretrols, sight glass, steam safety. Full stop without B2. |
| WH | Water heaters (tank + tankless) | Gas control valve, T&P, tank thermocouple/igniter, tankless flow/modulation & descaling. |
| CB | Combi units | Combi boiler + DHW combined systems (kept separate from B1/WH). |
| OIL | Oil-fired (dormant) | Oil burners, nozzles, pumps. Defined but inactive until oil service is offered in-market. |
Gate stacking. Combustion-dependent work on any fuel-burning unit (furnace, boiler, water heater, combi) also requires G2. Equipment gates stack with EPA/Electrical/Gas gates — a 3-phase heat pump's contactor swap needs E2; a boiler's combustion tune needs B1+G2.
One of novice / mid / senior / master. Tunes verbosity of the "how" guidance (a novice gets full step-by-step detail; a senior gets terser prompts) and establishes baseline eligibility for the override flag.
A distinct admin-granted permission (e.g., conditionalOverride: true, typically for senior/master). Lets a qualified tech proceed past a conditional hard stop (see B4). Proceeding requires an explicit on-screen acknowledgment that is stamped to the job with the Tech ID.
Each equipment category maps to a job-type template defining the suggested components to capture and the diagnostic entry points. Components are a suggested list (tech can skip/add), followed by the standard "other components?" gate.
Diagnosis is a loop: Claude proposes the next best check given everything known so far → tech performs it with the provided guidance → tech enters the actual value → Claude interprets and either advances, concludes, or stops. No pass/fail shortcuts; real data only.
Captured for every step: the value, timestamp, and tech ID — forming the diagnostic record.
A universal hard stop applies to everyone regardless of credential (e.g., gas-leak odor, active CO alarm, standing water on energized equipment). A conditional hard stop halts baseline/mid techs but a tech with the matching gate and the conditionalOverride flag may proceed after an acknowledgment.
| Trigger | Type | Behavior |
|---|---|---|
| Gas odor / suspected leak | Universal | Stop, evacuate/ventilate, shut gas, escalate — no override. |
| Active CO alarm | Universal | Stop, ventilate, shut down appliance, escalate. |
| Standing water + energized equipment | Universal | Kill power safely if possible, stop, escalate. |
| Suspected cracked heat exchanger | Conditional | Hard stop + red-tag + escalate for baseline/mid. A tech with G2 + override may proceed (combustion analysis, condemn/clear) after acknowledgment. |
| Readings that don't reconcile / low confidence | Conditional | Stop and escalate rather than guess; senior/master with override may continue. |
Every completed (or escalated) job stores a record that ties the work to the responsible technician and their credentials.
Claude is the reasoning engine, accessed through the same backend pattern as Stage 1 (server-held key; the app never calls the model directly). Calls:
Safety guardrail for the AI layer. Hard-stop conditions and gate evaluation are enforced in application logic, not left to the model alone. The model flags suspected danger; the app authoritatively halts, gates, and requires acknowledgments. The model is also instructed to escalate on low confidence rather than fabricate a next step.
The capstone that connects Repair to Sales: at the moment a repair is diagnosed and priced, the tool evaluates whether fixing this unit still makes sense — and, when it doesn't, turns the service tech into the replacement consultant. This is where a 20-year-old furnace with a $3,500 cracked-heat-exchanger repair becomes a new-system conversation instead of throwing good money after bad.
After a diagnosis with a repair estimate, and after any safety hard stop has already been actioned (see below). It evaluates: the repair estimate, the equipment's age and condition, and a remaining-useful-life heuristic per equipment type. A crossover fires when a high-cost repair lands on an end-of-life unit (e.g. repair cost is a large fraction of replacement, or age is past typical service life). Routine low-cost repairs (a capacitor, an igniter) never trigger it.
A transparent side-by-side the customer can see: repair now (the estimate + the unit's age and what's likely next to fail) vs. replace (new-system options, pulling in rebates and the Stage 1 Savings Profile). All figures follow the same estimate/range discipline as the savings profile — labeled estimates, never "guaranteed," and the repair cost is presented honestly, never inflated to push a sale.
If the customer leans replace, one tap opens the Sales survey pre-filled with the equipment already captured (nameplate, age, system type) and the diagnosis as context — the tech continues seamlessly into a quote. If the customer says "just fix it," the tool returns to the repair flow with nothing lost. Architecturally, Repair computes the recommendation and opens the Sales app with context; it does not embed Sales logic (the Stage 3 cross-tool link, per the Architecture doc §13).
Safety is absolute and comes first (Safety condition). The advisor never overrides or softens a hard stop. A cracked heat exchanger is red-tagged and the unit shut down regardless of whether a new system is purchased; the repair-vs-replace conversation happens after that safety action, never instead of it.
Field Engineer Stage 2 — Service Repair Copilot. Specification draft for planning, investor review, and development. Pricing and proposal features remain Stage 1's roadmap; installation tooling is a separate future stage.