Can a propane generator run on natural gas? Not safely as-is: a propane-only unit needs a factory dual-fuel or tri-fuel design, or a manufacturer-approved conversion kit. Anything else risks a wrong fuel-air mix, overheating and gas leaks, so check your data plate and manual first.
Check Your Generator Before Anything Else
The decision comes down to what the manufacturer built and approved. Work through these steps in order and stop at the first one that applies.
- Read the data plate. Look for the rating label on the frame or engine shroud. It lists the fuels the unit is certified for, and often the wattage for each fuel.
- Check the manual’s fuel section. Words like “LP only” or “propane only” mean natural gas is not approved. “Dual fuel” usually means gasoline plus propane. “Tri-fuel” adds natural gas.
- Look for a natural gas inlet. A tri-fuel unit has a separate natural gas connection and a fuel selector. A propane-only unit has just the one LP inlet.
- Ask the manufacturer. Give them your model and serial number and ask whether an approved natural gas kit exists for it.
- If the answer is no, do not modify it. Buy a unit rated for natural gas instead.
If you are still sorting out how propane-capable units work, our explainer on whether a generator can run on propane covers dual-fuel basics.
Why You Cannot Just Connect a Natural Gas Line
Propane and natural gas are different fuels, and the engine is set up for one of them. Three things differ.
Energy content
Natural gas holds about 1,030 BTU per cubic foot. Propane holds about 2,500 BTU per cubic foot, roughly 2.4 times more. To make the same power, the engine must draw far more natural gas by volume, so the mixer or carburetor has to be sized for it.
Pressure
Household natural gas is delivered at low pressure, around 7 inches of water column. Propane comes out of a tank at much higher pressure and passes through a regulator built for it. A propane regulator and hose fed from a house line will not deliver the flow the engine needs.
Fuel-air mix
A propane-only unit is tuned for propane’s richer fuel. Run it on a leaner, lower-energy gas and it can stall, run hot or backfire. Changing the mix is a job for approved parts, not guesswork, which is why this guide gives no jet or pressure settings.
Can a Propane Generator Run on Natural Gas With a Conversion Kit?
Sometimes, but only when the manufacturer makes a kit for your exact model. A kit typically swaps or modifies the mixer or carburetor and adds a regulator suited to natural gas.
Universal aftermarket kits exist for small engines, generally up to about 12 hp. They usually involve drilling the carburetor, and some remove the gasoline option afterward. Owners of compact inverter models report that a propane kit can lock the unit to that fuel, since the case has no room for multi-fuel parts. That is anecdotal, so confirm with the maker.
Warranty and emissions
- An unapproved conversion can void the warranty. Ask for written confirmation before you start.
- Changing the fuel system can also affect EPA and CARB emissions certification, which matters if you live in California or a state that follows its rules.
- A qualified technician should do the work, not a first-time DIY job.
Compare the kit and labor cost against the price of a tri-fuel unit. When a kit is discontinued or unavailable for your model, the comparison is over.
How Much Power You Lose on Natural Gas
Expect less output on natural gas than on propane, because the fuel carries less energy per cubic foot. Briggs & Stratton notes that most standby ratings are measured on propane, and gives a 20 kW propane unit producing about 18 kW on natural gas as an example. A conversion-kit vendor suggests derating by about 20%, and general sources put the loss versus gasoline at 10 to 20%. Your manual’s per-fuel wattage is the number to trust.
| Fuel | Energy per cubic foot | Output example (Briggs & Stratton) |
|---|---|---|
| Propane | about 2,500 BTU | 20 kW |
| Natural gas | about 1,030 BTU | about 18 kW |
Worked example: a 7,500-watt unit
Take a generator rated 7,500 watts on propane (a typical figure used here for illustration). A 10% loss leaves 6,750 watts. A 20% loss leaves 6,000 watts. If your essentials add up to 6,500 watts, the 20% case falls short, so size by the lower number.
Fuel cost per hour also differs by fuel and local rates; see what it costs to run a generator for the method.
Who Should Do the Gas Hookup and What to Watch For
Have a licensed plumber or gas fitter run the line. Piped gas work usually requires a permit and inspection under local code, which in the US follows NFPA 54 for natural gas and NFPA 58 for propane. Your local rules decide the details.
- Line sizing: the installer sizes pipe for the generator’s gas demand in BTU per hour, plus your other gas appliances.
- Manual shutoff valve: kit instructions call for one on piped natural gas, placed where you can reach it.
- Leak test: brush soapy water on every fitting and look for bubbles. Never use a flame.
- Outdoors only: run the generator outside, well away from windows, doors and vents, following the manual’s clearances.
- CO alarms: keep working carbon monoxide alarms in the home, on every level and near bedrooms.
If you smell gas, leave, shut off the supply if it is safe to do so, and call the gas utility or 911 from outside.
Natural Gas vs Propane: The Real Trade-Offs
Natural gas wins on convenience. Propane wins on output and independence from the utility.
- No refueling: a piped line means no tank swaps and no running out mid-outage, which is the main reason people ask this question.
- Lower output: you give up some watts, as the example above shows.
- Dependence on the utility: if the gas main is shut off or pressure drops in a regional emergency, your generator stops. A propane tank keeps working regardless.
- Maintenance: Briggs & Stratton lists a spark plug gap of about 0.020 to 0.021 in. for natural gas and 0.024 to 0.026 in. for propane, so follow your engine manual when you service it.
If you are weighing fuel types against battery options instead, see gas generator vs power station. For a gas-fueled setup, look for models rated and labeled for natural gas, such as dual-fuel or tri-fuel units, and compare their per-fuel wattage on the data plate.
Our Top Picks
Ready to shop? These are the top-rated options from our related roundup, Best Gas Generators For Home Backup Power of 2026.
PowerSmart 3800 Watt Dual Fuel Inverter Generator Quiet Portable Gas Propane with CO Sensor RV Ready
Pulsar PG1202SA 1200W Portable Gas Generator with Handle - Compact Camping Powerhouse
PowerSmart 1200W Portable Gas Generator 900W Rated 2-Stroke 39 lbs for Camping Emergency
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Frequently Asked Questions
Can I convert a gasoline generator to natural gas?
Only with a kit approved for your specific model, or by choosing a tri-fuel unit. Universal kits exist for small engines, but they can remove the gasoline option and may void the warranty. Check with the manufacturer and use a qualified technician.
Is a dual-fuel generator the same as a tri-fuel generator?
No. Dual-fuel usually means gasoline and propane. Tri-fuel adds natural gas and has its own inlet and fuel selector. A dual-fuel unit is not approved for natural gas unless the manual says so.
Can I connect my propane generator to the house gas line with a hose?
No. A propane-only unit is not set up for natural gas pressure or flow, and a makeshift hose connection risks leaks and a bad fuel mix. Piped gas requires approved parts and a licensed gas fitter.
Do I need a permit to hook a generator to my gas line?
Often the work needs a permit and inspection, depending on your local code. Ask your building department before the plumber starts. The installer will usually pull the permit and confirm the line is sized for the generator.
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