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Generac GP18000EFI

Generator. Specs from the manufacturer page (checked ).

Generac GP18000EFI
Photo: Generac

The Generac GP18000EFI is a portable generator with 18,000 W running output and 22,500 W starting output, powered by an 816cc engine with Electronic Fuel Injection. The manufacturer rates it at up to 9 hours of runtime at 50% load. It has electric start with the battery included and a never-flat wheel kit for moving it around.

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Running
18000W
Peak / surge
22500W
Run time @50 %
9h
CO shutoff
Yes
Weight
200.9kg

Key features

What it is for

Specifications

Running watts18000 W
Peak / surge22500 W
Tank54 L (14.3 gal)
Run time at 50 % load9 h
CO shutoffYes
AC output voltage120/240 VAC
Weight200.9 kg (442.9 lb)
DimensionsLength 39.5 in (100.3 cm), Width 30.9 in (78.5 cm), Length 36.5 in (92.8 cm)

From the Generac page. Values the manufacturer does not publish are left out.

What is in the box

Similar inverter & portable generators

All Generac models →

Connection and wiring

Follow the diagrams in the Generac manual. Connecting to a home panel needs a transfer switch or interlock and a licensed electrician.

Error codes and troubleshooting

CodeMeaningWhat to doManual page
1-1Carbon monoxide is above the limit, or input voltage to the COsense module is below normal range. COsense shuts off the engine when CO accumulates.Move generator outside, away from windows, doors, and vents, and point the exhaust away from people and buildings. Contact an IASD. Call service if it persists.9
1-2Battery voltage is above the normal operating range.Contact an IASD. Call service if it persists.9
1-3Battery voltage is below the normal operating range.Charge the battery to the correct level.9
5-2No or low fuel, or engine speed is below the normal operating range.Fill the fuel tank. If the fault persists, contact an IASD. Call service if it persists.9
6-1Low oil pressure, or the oil pressure switch voltage is not detected. The low oil pressure shutdown system stops the engine.Fill the crankcase to the correct oil level. Contact an IASD. Call service if it persists.9
OtherMultiple faults are present. The manual lists no specific condition for this entry.Contact an IASD for the full list of fault codes. Call service if it persists.9

From the Generac manual. All 6 GP15500EFI / GP18000EFI codes →

FAQ

How long does the Generac GP18000EFI run on a tank?

The maker rates it at 9 hours at 50 % load (about 9,000 W) on a 14.3-gal tank. A light load such as a refrigerator and lights runs longer; a full load runs shorter.

Can the Generac GP18000EFI start a sump pump or well pump?

Starting surge matters more than running watts: this unit is rated 22500 W peak. That covers a typical 1/2 HP sump pump (about 2150 W to start). Use the calculator with your exact pump.

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