Your generator threw a code. Here’s the verdict.

Honestly: it diagnoses your generator. A surprising share of fault codes are genuinely homeowner-resolvable — a closed fuel valve, an LP tank run too low, a battery at end of life, an aux shutdown switch bumped off, a generator breaker left off after service. The diagnostic works those branches first, in order.

Some codes are dealer-only by design — fuel pressure measurement, alternator internals, transfer-switch work. When yours is one of those, the verdict tells you plainly, names the test the dealer should run first, and gives you the typical cost. Knowing that before the truck rolls is worth money by itself: a service visit averages $273 before any part is touched.

Generac’s support articles are good — we cite them, and for codes like 1100 they’re the source behind our checks. But each article covers one code in isolation, stops at “contact an IASD,” and never asks the questions that separate the causes: cranks or not, NG or LP, battery holding under load or not. GenVerdict runs one branching flow across all the codes plus your symptoms, and adds the two things Generac will never publish against its own dealer network: honest dealer-only verdicts and what the dealer visit should cost.

Generac home standby units with Evolution controllers are first-class — the Guardian and Next Generation air-cooled lines — and the core e-Codes carry over to older Nexus controllers. The kit also decodes Kohler’s plain-text faults (RDC2 controllers: “Over Crank,” “Spd Sens Flt,” “Volts L1-L2 Low”…) and Cummins Onan’s two-digit blink codes, with a side-by-side equivalence table. Portable generators and commercial/industrial sets use different systems and aren’t the focus.

Yes. Enter your code, answer the branch questions, get your verdict — no email address, no account. The kit is there for when you want the complete decoder, the deep-dives, and the cost map in one place.

Use it to understand the problem — then call the dealer first. Generac-certified technicians routinely warn that repairs beyond basic checks can void warranty coverage, so on a warrantied unit the dealer call is the first move. You’ll make that call knowing what the code means and which test should happen first, which changes the conversation.

The checks here are deliberately conservative: valves, tank gauges, dipsticks, switches, breakers, battery terminals, and watching how the machine behaves. The tool never asks you to open the transfer switch, measure fuel pressure, adjust a regulator, bypass a safety shutdown, or test live voltage — those are hard dealer-only lines throughout, because on a standby generator the wrong DIY step involves lethal voltage or gas under pressure. If you smell gas, stop and call your gas supplier or a professional — that’s not a symptom to troubleshoot.

The full decoder for 25+ Generac codes and the battery/charger warnings, Kohler and Cummins Onan equivalence tables, the battery triage deep-dive (load testing, voltage thresholds, charger chain), the fuel triage deep-dive (NG vs LP, pressure falloff, fuel selection), the exercise-failure playbook, the storm-season readiness checklist including the extended-outage routine, and the dealer cost map with an interactive quote checker. Everything is sourced from manufacturer support pages, diagnostic manuals, and published cost data.

One payment of $39, and you’re redirected straight to your private kit page — no account to create, no login to remember. Bookmark it; it’s yours to keep.