Generac · Generator Serious

1100 — Generac 1100 — Overcrank (Engine Failed to Start)

Alarm 1100 is Overcrank: the engine cranked through all of its start attempts but failed to start, so the controller stopped trying. It is NOT a low-oil-pressure code (that is 1300). (Meaning corrected against official Generac support documentation / Evolution controller e-code list; older Nexus controllers may differ — confirm for your unit.)

Keep using it?
Limited use only
DIY difficulty
Moderate
Verified against
support.generac.com ↗

How to fix it

  1. Confirm the fuel supply: gas shutoff valve fully open, adequate LP/natural-gas pressure.
  2. Load-test the starting battery and check connections.
  3. Inspect and re-gap or replace the spark plugs.
  4. Attempt a manual start; if it still overcranks, have a dealer check fuel delivery.

Why it happens

Typical signs: Generator will not start during an outage or exercise · 1100 / Overcrank in the alarm log · Engine cranks but does not fire

  • No fuel / gas supply Closed gas shutoff valve, low gas pressure, empty/low LP tank, or a fuel regulator problem.
  • Weak or dead starting battery Not enough cranking power to start.
  • Fouled or worn spark plugs Weak spark prevents starting.
  • Fuel delivery / mixture fault Choke, solenoid, or carburetor issue.

Parts you may need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

  • Generac generator spark plugs Common replacement
    Amazon →
  • Generac standby generator battery Common replacement
    Amazon →

More Generac generator codes

1300 1300 — Low Oil Pressure Shutdown 1501 1501 — RPM Sense Loss 1505 1505 — Overcrank (Variant — Try Again) 1600 1600 — Underspeed 1800 1800 — Overvoltage 1900 1900 — Undervoltage

All Generac codes → All generator codes →

Frequently asked questions

What does the 1100 code mean on a Generac generator?

Alarm 1100 is Overcrank: the engine cranked through all of its start attempts but failed to start, so the controller stopped trying. It is NOT a low-oil-pressure code (that is 1300). (Meaning corrected against official Generac support documentation / Evolution controller e-code list; older Nexus controllers may differ — confirm for your unit.)

What causes the 1100 code on a Generac generator?

No fuel / gas supply: Closed gas shutoff valve, low gas pressure, empty/low LP tank, or a fuel regulator problem. Weak or dead starting battery: Not enough cranking power to start. Fouled or worn spark plugs: Weak spark prevents starting.

Is it safe to keep using a Generac generator with a 1100 error?

Limited use only. This is rated a serious-severity fault.

How do I fix 1100 on a Generac generator?

Confirm the fuel supply: gas shutoff valve fully open, adequate LP/natural-gas pressure. Load-test the starting battery and check connections. Inspect and re-gap or replace the spark plugs.

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: support.generac.com.