Diagnostic Visit Intake and Repair Authorization

Purpose

A diagnostic visit's only product is information. It either ends with a decision the customer agreed to in writing or it ends with a second trip nobody gets paid for. This procedure guarantees three artifacts exist when the tech leaves: a named failed component backed by a measurement, a written authorization carrying a scope and a ceiling, and an appliance left in a condition the customer repeated back.

The failures it prevents are ones every shop owns. A board ordered against a symptom instead of a reading, which returns the same complaint and a non-returnable part. A customer who approved a pump and disputes the drain hose. A gas range left with the shutoff closed, no tag, and a family who opens it again that evening.

Scope

Residential in-home diagnostic calls on major appliances: refrigeration, laundry, dishwashers, cooking equipment, over-range microwave and hood. Arrival through signed authorization and close-out.

Not covered: technical diagnosis of a refrigeration sealed system, which its own SOP owns and step 4 hands off to; the repair-or-replace consultation, which step 6 routes to. On a warranty call the claim administrator authorizes covered parts, and anything outside the claim still needs the customer's signature on the same ticket. Commercial and coin-op equipment authorize through a property manager on a purchase order.

Roles and the handoff between them

Before the cover comes off

Each of these is a hazard the diagnosis itself creates, so they precede it.

Electric. Unplug at the receptacle. Where the unit is hardwired or the receptacle is trapped behind it, open the breaker, then prove the appliance dead at the terminal block with a meter proved live on a known source before and after. That sequence is NFPA 70E-2021, 120.5; the work practice for this class is 29 CFR 1910.333(b)(2), not 1910.147, which excludes electrical utilization work at its own (a)(1)(ii)(C).

Gas. Close the appliance shutoff before pulling a range forward, because the flexible connector is what the move damages. On any gas odor everyone leaves the building immediately, no switch touched, no light turned on, no phone used inside, and the utility is called from outside.

Water plus electricity. On a dishwasher, washer, or icemaker call with standing water, open the circuit before a hand or a towel goes into the pan.

Stored energy. A microwave high-voltage capacitor holds a lethal charge after unplugging; discharge it through a resistor across its terminals before anything else in that cabinet is touched.

The procedure

1. Confirm the appliance from its own data plate. Read model and full serial: fresh-food liner on refrigeration, door strike on laundry, tub rim on dishwashers, frame behind the bottom drawer on ranges. Acceptance: both transcribed character for character and matching the booking. Wrong looks like a model differing from the ticket, common where the customer read a marketing name off the door. Stop and correct the ticket before any parts lookup; a part ordered against the wrong model is the costliest error here. Slide a range on hardboard, two people, never walked on its feet.

2. Take the complaint verbatim, then reproduce it. Write what they said ("it fills, then just hums") and separately what you observed. Acceptance: you witnessed the failure, or you wrote the exact reason you could not plus the conditions that would produce it. Wrong looks like a complaint accepted on description and never seen; intermittents diagnosed that way come back at a rate no shop absorbs. Stop rule: if it will not reproduce in the time allowed, name no part and book it unreproduced.

3. Establish supply before opening the appliance. Measure voltage at the receptacle, water at the stop, or gas manifold pressure, by type. Acceptance: voltage inside the plate's band, water flowing at the stop, manifold pressure at the plate value for the fuel supplied. Wrong looks like condemning a fill valve on a dishwasher fed by a stop a plumber left half closed. Stop rule: out-of-spec supply is upstream of your scope, so document the reading and hand it back as a plumbing or electrical call. Do not break a gas union for a reading with an ignition source in the room.

4. Open only what the complaint requires, unit proved dead. Remove the panel reaching the suspected system and no others, fasteners in a tray. Acceptance: that panel off, appliance still proved dead at the terminal block. Wrong looks like a full teardown on a hunch, which turns a 40-minute diagnosis into a 2-hour one and leaves three disturbed connections to explain. Stop rule: if access requires disturbing a sealed refrigeration line, a gas union, or a factory crimp, route to the SOP that owns it. Cut-resistant gloves before a hand enters a cabinet.

5. Isolate to one named component with a measurement. Take the reading the tech sheet calls for: winding resistance, continuity across a thermal fuse, a switch state, supply voltage at the component, or stored fault history. Acceptance: a number or state written next to the published value for that model. Wrong looks like "board is bad" with nothing beside it. Stop rule: no indicting measurement means the diagnosis is unfinished, so continue or book it undiagnosed, but sell no part. Metering a live control circuit is energized work: intact lead insulation, one hand, stance clear of the cabinet.

6. Confirm the part exists and lands in a stated time before quoting. Get an availability answer against the confirmed model, not a listing. Acceptance: part number matched to the model plus a supplier with stock or a stated lead time. Wrong looks like a quote given on a part later found discontinued, which forces a second conversation from a weaker position. Stop rule: discontinued, indefinitely backordered, or used-only means quote no repair; convert to a repair-versus-replace consultation and record why.

7. Write scope, ceiling, and return condition, then get it signed. Scope names the component. Ceiling is the authorized total including labor and the diagnostic credit, read before signing. The return condition states what happens if the named part does not resolve the complaint. Acceptance: signature or recorded electronic acceptance carrying all three plus the date. Wrong looks like verbal approval later remembered differently. Stop rule: no signature, no ordered part.

8. Leave the appliance in a stated condition and say the sentence out loud. Reassemble what you opened, restore or deliberately withhold supply, and tell the customer which. Acceptance: the customer repeats back whether it may be used. Wrong looks like a range left with the shutoff closed and no tag. Stop rule: unsafe to operate means close the supply, red-tag it naming hazard and date, and note the customer was told. Never leave a gas appliance disconnected without capping at the shutoff.

The record this produces

One diagnostic ticket, which is what the shop actually sold on this visit.

• Identity: model, full serial, manufacture date where the serial encodes it, install date if known. These land on the equipment record and are what the parts desk reads on every future call for this appliance.
• Complaint: the customer's verbatim words, and separately the observed condition with the conditions that produced it.
• Diagnosis: the measurement, the published value it was compared against, and the component indicted. A warranty administrator reads this if the part fails inside its own warranty; the next tech reads it before returning.
• Commercial: part number, availability answer with its date, ceiling, scope sentence, return condition, signature and timestamp.
• Close-out: in service or out of service, red tag yes or no, and what the customer was told.

The owner reads close-out fields on any call that becomes a complaint, and an unanswerable one is where a dispute stops being the customer's memory and becomes the shop's problem.

One run of this procedure, filled in

Front-load washer, drains but will not spin, booked from a phone description.

• Step 1: plate under the door strike reads a model two digits off the booking. Ticket corrected. Pass.
• Step 2: customer's words, "it drains and then just sits there and beeps." Reproduced on rinse-and-spin: drain completes, drum attempts rotation twice, control posts a code. Pass.
• Step 3: 121 V at the receptacle, inside the plate's 108 to 132 V band. Pass.
• Step 4: rear panel only, unplugged, proved dead at the terminal block. Pass.
• Step 5: stored fault history points at the door lock circuit. The lock measures open on the switch leg the tech sheet says should close, with 0 V at its control input while the control commands it. Component: door lock assembly. Pass.
• Step 6: part number confirmed against the corrected model. Supplier reports the assembly superseded twice, current number on indefinite backorder, no date offered. Fail, stop rule taken, no repair quoted.
• Step 7: not executed. The visit converted to a repair-versus-replace consult. The washer is 9 years old against a published residential washer life expectancy near 10 years, and the only obtainable assembly is used with no warranty: two of that SOP's four gates, so the call went to replacement.
• Step 8: left in service with a spoken warning that the lock may hold the door closed at end of cycle, repeated back. No red tag; the failure mode is inconvenience, not hazard.

Step 5 passed cleanly and step 6 still stopped the job. A correct diagnosis is not by itself an authorization to sell a repair, which is why availability is a gate rather than a task for the office afterward.

When the call does not match this procedure

Out of scope on arrival. Integrated built-in refrigeration, commercial equipment in a residence, or a brand your shop has no parts access to. Collect only the disclosed trip fee, say plainly you are not the right shop, and note the reason so dispatch stops booking it.

The customer refuses the diagnostic fee at the door. Do not open the appliance. Leave and let office decide.

A second unrelated fault appears mid-repair. Stop at the ceiling, call, describe the second fault and its own price, and take a second authorization line before touching it. The common version of this dispute is a tech who fixed both because he was already there.

Nobody with authority is present. A tenant does not authorize work on a landlord's appliance. Whether a particular signature binds the owner is a question for the shop's own attorney; the operational fact you can bank is a named authorizer with a timestamp.

The assumed condition is absent. No power at the panel, water off at the street, the appliance already part-disassembled. Photograph it before touching anything and reprice from that condition, not the booked one.

References

• 29 CFR 1910.333(b)(2), work practices for electrical work; 29 CFR 1910.147(a)(1)(ii)(C) for the carve-out that sends utilization work there.
• NFPA 70E-2021, 120.5, live-dead-live proving sequence.
• NFPA 54 / ANSI Z223.1 National Fuel Gas Code, in the edition your AHJ has adopted.
• Manufacturer tech sheets for the model in hand, the source of every published value step 5 compares against.
• See related: the repair-versus-replace recommendation standard, and the sealed-system diagnosis visit SOP.