What you are actually buying
A diagnostic is not a repair and it is not an estimate. It is a professional opinion about what is wrong, supported by testing, delivered in writing. That distinction is why the fee is legitimate — and why a diagnostic that ends in a verbal guess has not delivered what you paid for.
The deliverable is the thing to negotiate. Before booking, ask what the written finding will contain. A useful one names the tested conditions, the identified cause, and the proposed correction. A weak one names a part.
What the fee typically covers
A service call runs $150 to $300 and is credited toward the repair if you proceed. That range covers a standard residential visit with monitoring review, accessible electrical testing, and a written finding.
It does not automatically cover roof access, a lift, extended travel, or a second visit after parts are ordered. Those are the items that change the number, and they are worth confirming before anyone is dispatched.
| Item | Usually included | Worth confirming |
|---|---|---|
| Monitoring and production history review | Yes | Whether prior years are compared |
| Accessible electrical testing | Yes | Which conditions are tested |
| Written finding | Yes | Whether it names the cause or only the part |
| Roof access | Sometimes | Whether the fee changes for under-array work |
| Travel beyond the service area | No | Whether a trip charge applies |
| Follow-up visit after parts arrive | No | Whether it is included or billed |
| Repair credit | Policy-dependent | The exact condition attached to the credit |
Remote review, site diagnostic, and inspection are three different things
A remote review looks at monitoring data and records without visiting. It is cheap, fast, and sufficient for a surprising share of reporting problems. It cannot test a connection or find a roof condition.
A site diagnostic adds physical testing at the equipment. An inspection is broader still, and produces a condition report rather than a fault finding. Booking the wrong one is the most common reason a homeowner feels the fee was wasted.
- Reporting stopped, production apparently normal — start with a remote review.
- System down or underproducing in daylight — a site diagnostic is usually required.
- Buying, selling, or planning maintenance — that is an inspection, not a diagnostic.
What happens if more testing is needed
Some faults are not resolvable in one visit. A fault that only appears under high load, an intermittent connection, or a condition under the array may require a return visit or specialized testing.
That is normal, and it should be described in advance. Ask what the next step costs if the first visit is inconclusive, and get that answer before authorizing the work rather than after.
The booking checklist
Use this list before you authorize a visit. A provider who can answer all of it is scoped; one who cannot is improvising.
- What is the visit charge, and is it credited toward the repair? Under what condition?
- What testing is included, and what is billed separately?
- Is roof access included, and does the fee change if it is needed?
- What written finding will I receive, and when?
- Is travel included for my address?
- If the fault needs a second visit, what does that cost?
- Who performs the work, and what licensing applies?