How to Convert a Generator to Natural Gas

Why convert a generator to natural gas

Natural gas is a common household fuel, delivered through pipelines in many areas. Using it to power a generator can eliminate the need to store liquid fuel, but converting requires a kit. The U.S. Energy Information Administration (EIA) explains that natural gas is a fossil fuel energy source with methane as its largest component. If you're comparing fuel options, see our natural gas vs propane article.

If your home already has natural gas service, a converted generator can run for as long as the supply lasts, provided the installation is done correctly. However, you must follow the same carbon monoxide safety rules as with any engine-driven generator. The CPSC warns that one portable generator can produce as much CO as hundreds of cars, so outdoor placement and CO detectors are not optional. For more on fuel flexibility, see dual fuel generators.

What a tri fuel conversion kit includes

A tri fuel conversion kit allows a gasoline generator to also run on propane and natural gas. The typical kit contains a gas regulator, a mixing device, a throttle linkage, and hoses. The regulator controls the pressure of the natural gas entering the engine, and the mixer blends the gas with air. If you're looking for a generator that already supports multiple fuels, check our best tri fuel generators list.

Some generators come from the factory as dual fuel or tri fuel. If you are starting from a gasoline-only model, you need to verify that a conversion kit exists for your exact engine. Kits are not universal, and using the wrong one can create a dangerous fuel or carbon monoxide condition. Before purchasing, make sure you understand the differences between fuel configurations.

Installation steps for a natural gas conversion

Follow the kit manufacturer's instructions precisely. As a general sequence, you will turn off the generator and let the engine cool, disconnect the gasoline fuel line and remove the carburetor if required, mount the regulator and mixer, connect the natural gas supply line, and then check all connections for leaks. For a similar process with propane, see how to convert generator to propane.

The gas line connection is the most critical step. Natural gas is supplied at a pressure that your generator's carburetor cannot handle directly. The regulator steps the pressure down to a safe level. Because a mistake can cause a gas leak, a qualified professional should perform the final hookup to your home's gas system.

After installation, you must test the generator outside, far from doors, windows, and vents. The CDC recommends operating generators outdoors more than 20 feet away from any window, door, or vent. Review the generator safety checklist before your first test.

• Turn off and cool the generator completely.
• Disconnect the gasoline fuel line and drain the carburetor bowl if present.
• Mount the regulator and mixer according to the kit instructions.
• Connect the natural gas line with the approved gas hose and fittings.
• Inspect every fitting for leaks using a soap-and-water solution.
• Start the generator and observe the exhaust for proper combustion.

Safety checks after converting

Carbon monoxide is colorless and odorless, and exposure can be fatal. The EPA states that CO can kill you before you are aware it is in your home. Never run a converted generator inside a home, garage, crawlspace, or shed, even with doors and windows open. For more on proper placement, read where to place a CO sensor.

Install battery-operated CO detectors on every level of your home and outside sleeping areas, following the CDC guidance. Check the batteries twice a year, such as when you change clocks. Also consider a detector with a digital readout that shows the highest CO level recorded.

Inspect the hoses and fittings before every run. Natural gas leaks can occur at connections, and a small leak near the generator can become a fire hazard. Have a professional evaluate the entire fuel system at least once a year. For overall maintenance, see our guide on generator safety.

What to pick for your natural gas generator needs

Questions

Can any portable generator be converted to natural gas?

Only generators with a compatible engine and carburetor can use a conversion kit. You need to check with the kit manufacturer for your specific model. Look for models that support natural gas out of the box if you want a simpler solution.

Is it safe to run a converted generator indoors if the doors are open?

No. The CPSC and CDC warn that portable generators can kill you indoors, even with ventilation. Always operate the generator outside, more than 20 feet from any window, door, or vent.

Do I need a professional to install the natural gas line?

Yes. Connecting to your home's natural gas supply involves pressurized gas. A licensed plumber or gas fitter should make the final connection and check for leaks. Improper installation can create a fire or explosion risk.

Will converting my generator void the warranty?

Most manufacturers do not approve aftermarket conversion kits, and installing one can void the engine warranty. If warranty coverage matters to you, consider buying a generator that is factory set for natural gas.

What are the most important safety checks after converting?

Place the generator outdoors away from openings, install CO detectors, and inspect all gas hoses for cracks and loose fittings. Also test for leaks with soapy water and have a professional verify the system before first use.

Does running on natural gas reduce the generator's maximum power?

Natural gas contains less energy per volume than gasoline, so the generator may produce slightly lower output. You should account for this when planning loads. However, the effect on typical home backup use is often small.