How do I configure the fuel type on my air-cooled home standby generator?

Most Generac air-cooled units are factory-set for natural gas (NG). Many models also support operation on liquid propane (LP). For supported models, configure the fuel selection during initial setup and verify the control panel fuel configuration is set correctly for the installed fuel source.

This article includes

• Environment
• Fuel configuration considerations
• Configure fuel type — Next Generation series
• Configure fuel type — Guardian series
• Configure fuel type — 7.5 kW PowerPact
• Can my home standby generator run on gasoline?
• Can I switch my fuel source back and forth?
• Additional Information

Environment

• Generac Next Generation Series 10-28 kW air-cooled standby generators
• Generac Guardian Series 10-26 kW air-cooled generators (2017 to present)
• Generac 7.5 kW PowerPact air-cooled generator

For information regarding fuel configuration on liquid-cooled home standby models, reference the Can I Convert a Liquid-Cooled Standby Generator to Run on a Different Fuel Source? article.

Fuel configuration considerations

• Generac customer support cannot size gas lines, tanks, or regulators. We can provide BTU’s and fuel pressure in inches of water column, which will help your installer correctly size these items: How Do I Determine the Fuel Line Sizing for My Air-Cooled Home Standby Generator?
• Proper fuel flow is critical for generator operation under a full load. Determining fuel pressure requirements can be done by referencing the How Do I Determine the Proper Fuel Pressure for My Air-Cooled Home Standby Generator? article.
• Fuel lines MUST be sized for a full load.
• Fuel consumption (listed in ft³/hr) can be located on the spec sheet.
• If the fuel pressure is too high or too low, the generator will not operate smoothly. The Troubleshooting Low Fuel Pressure Issues in Air-Cooled Home Standby Generators article contains more information regarding this issue.

Configure fuel type — Next Generation series

For Next Generation series generators, fuel selection must be configured in the Field Pro app during initial setup prior to the first startup using the guided setup process, or in the generator configuration settings. If you need assistance with a fuel conversion, contact a Generac authorized service dealer.

Configure fuel type — Guardian series

Note: On older generators, the knob can get stuck in place. If this happens, gently tap on it with a rubber mallet or similar tool to loosen and turn. Use caution and do not force the knob.

Note: If the orange lever in the image shown below is not present, then the generator likely does not have this fuel conversion capability, and fuel jets will need to be swapped out.

Configure the Guardian control panel for the correct fuel selection

The control panel will also need to be configured for the appropriate fuel type:

1. Press ENTER to bring up the main menu. 
2. Use the arrow keys to navigate to the SUB MENUS selection and press ENTER.
3. Use the arrow keys to navigate to the EDIT menu and press ENTER.
4. Use the arrow keys to select the Fuel Selection menu and press ENTER. 
5. Use the arrow keys to toggle the appropriate fuel selection and press ENTER. 

Configure fuel type — 7.5 kW PowerPact

The 7.5 kW PowerPact requires swapping mechanical fuel jets. Reference the PowerPact installation manual for more information: Where can I find an installation manual for my home standby generator?

The generator was configured for natural gas (NG) operation at the factory. The following procedure will enable the generator to operate on LP vapor fuel.

1. Remove the four 6mm Allen head fasteners and lift the top lid from the generator enclosure.

2. Remove the two 4mm Allen head fasteners. Lift and remove the rear panel.

3. Use a pliers to squeeze the hose clamp and slide from the fuel inlet fitting.

4. Remove the hose from the fuel inlet.

5. Remove the Natural Gas (NG) fuel jet from the fuel inlet. If the nozzle is found to be inside the hose, remove it with a needle nose pliers.

6. Locate the fuel jet for propane use (supplied). It has a smaller inside diameter than the NG jet.

7. Insert the propane fuel jet into the end of the fuel inlet.

8. Reinstall the hose onto the fuel inlet. Secure the hose with the clamp.

9. Verify the hose has not been kinked in any way.

10. Reinstall the rear access panel by hooking it on the top of the unit. Check to be sure the alternator bellow is completely secure around the frame provided on the access panel. Attach the panel firmly to the unit with the 2 shorter Allen screws.

11. Reinstall the top lid firmly with the 4 long Allen screws.

Can my home standby generator run on gasoline?

• No. Generac residential home standby generators are only designed to run on natural gas and liquid propane fuel sources. Any modification or improper changes to the fuel system may compromise warranty: What will compromise the home standby generator warranty?
• Generac home standby generators are not compatible with dual fuel carb kits.

Can I switch my home standby generator fuel source back and forth between natural gas and liquid propane?

While we understand the importance of having flexibility, we do not recommend changing a home standby generator's fuel source on an as-needed basis. See here for more information: Can I switch my home standby generator fuel source back and forth between natural gas and liquid propane?

Additional Information

• If NG pressure is too low, and the gas company cannot provide the necessary pressure, the owner will need to consider switching to LP fuel.

• Incorrect fuel pressure, undersized lines, or improper fuel modifications are not covered under warranty: What will compromise the home standby generator warranty?

• Owners should refer to the owner’s/install manual for fuel conversion instructions on the PowerPact 7.5 kW and liquid-cooled units.

  • How Do I Find a Copy of My Home Standby Generator Owner's Manual?

  • Can I Convert a Liquid-Cooled Standby Generator to Run on a Different Fuel Source?