Kohler natural gas home generators connect to the gas line your home already has, so they can run through a long outage with nothing to refill. That is their big advantage. The catch is that every model makes a little less power on natural gas than on propane, and your gas meter and piping have to be big enough to feed it.
This guide deals with the natural gas side only. You will see each Kohler’s rating on natural gas, exactly how much gas the popular models burn at each load, the gas pressure and pipe sizes Kohler asks for, and the questions to put to your installer and your gas company.
The figures come from Kohler’s official website and from Kohler’s own specification sheets for the 20RCA and 26RCA. We have not installed or tested these generators.
Kohler on natural gas at a glance
Endless fuel, slightly lower ratings, and a gas line that must keep up
Ratings and fuel figures come from Kohler’s product pages and Kohler spec sheets G4-272 and G4-315, checked in October 2026.
Quick answer
Every Kohler home standby generator runs on natural gas or propane. On natural gas the ratings are lower: the 14RCA gives 12 kW, the 20RCA gives 18 kW and the 26RCA gives 24 kW. A 20RCA burns 161 cubic feet of gas an hour at half load and 281 at full load. Kohler’s spec sheets ask for a supply pressure of 3.5 to 11 inches of water column and a gas pipe of 1 inch or larger, depending on the distance. Have your installer confirm that your meter can supply the generator together with your other gas appliances.
How we put this guide together
We have not installed or tested these generators. Natural gas ratings and half-load fuel figures come from Kohler’s official product pages. Full-load figures, gas pressures, pipe sizes and derating rules come from Kohler’s specification sheets for the 20RCA (G4-272) and the 26RCA (G4-315). Product box details come from current Amazon listings. We do not publish prices. Gas work is regulated, so treat this guide as preparation for a conversation with a licensed installer, not as instructions.
In this guide
- Why Choose Natural Gas for a Home Generator?
- Kohler Ratings on Natural Gas vs Propane
- How Much Natural Gas Does a Kohler Generator Use?
- Gas Pressure, Meter and Pipe Size
- Altitude and Heat Reduce the Rating
- Natural Gas or Propane for a Kohler?
- What a Natural Gas Installation Involves
- Buying a Kohler for Natural Gas
- Running a Kohler on Natural Gas Through a Long Outage
- Common Mistakes With Natural Gas Generators (and the Fix)
- Pro Tips for a Natural Gas Kohler
- Real-Life Scenarios: Does Natural Gas Fit?
- Kohler Natural Gas Home Generators: FAQ
- Your Natural Gas Generator Checklist
Why Choose Natural Gas for a Home Generator?
Kohler’s home standby generators burn one of two fuels: natural gas or liquid propane. Kohler’s own FAQ says they connect directly to your existing natural gas line or to a propane tank on your property.
If your street has gas service, natural gas is usually the easier choice.
- It does not run out. The gas arrives through a pipe, so there is no tank to watch during a week-long outage.
- There is nothing to store. No cans, no cylinders, no deliveries.
- It is already at the house. Kohler notes that installation cost depends partly on whether your fuel source is already connected.
- Nobody has to refuel in a storm. Kohler sums it up as “no refueling or extension cords.”
There are trade-offs too, and it is better to know them now.
- Lower output. Most models make about 8 to 14% less power on natural gas.
- You rely on the gas utility. Gas service is usually very dependable in an outage, but it is not guaranteed in every disaster.
- Your gas system may need work. The meter or the pipe may be too small for a generator.
Key insight: on natural gas the fuel never runs out, but the flow can fall short. Most natural gas generator problems are really gas supply problems.
Kohler Ratings on Natural Gas vs Propane
A kilowatt rating printed in a model name is the propane rating. The natural gas rating is the smaller number beside it.
| Model | Type | Rating on LP | Rating on NG | Difference |
|---|---|---|---|---|
| 12RESV | Air-cooled | 12 kW | 11 kW | 1 kW less |
| 14RCA | Air-cooled | 14 kW | 12 kW | 2 kW less |
| 20RCA | Air-cooled | 20 kW | 18 kW | 2 kW less |
| 26RCA | Air-cooled | 26 kW | 24 kW | 2 kW less |
| 24RCLA | Liquid-cooled | 24 kW | 21 kW | 3 kW less |
| 48RCLC | Liquid-cooled | 48 kW | 48 kW | None |
In amps, Kohler’s spec sheets list the 20RCA at 75 amps on natural gas and the 26RCA at 100 amps, both at 120/240 volts.
Two things are worth noticing.
First, size the generator on the natural gas number. If you will run a 20RCA on natural gas, you own an 18 kW generator. Plan your loads around that. Our free Generator Size Calculator adds up your appliances for you.
Second, the gap is not the same on every model. The 48RCLC is listed at 48 kW on both fuels, while the 14RCA drops from 14 to 12 kW.
How Much Natural Gas Does a Kohler Generator Use?
Natural gas is measured in cubic feet. Generator spec sheets give fuel use in cubic feet per hour, written as cfh.
Kohler publishes the figure for every load level on its two most popular air-cooled models.
| Load | 20RCA on natural gas | 26RCA on natural gas |
|---|---|---|
| Weekly exercise | 71 cfh | 67 cfh |
| 25% load | 127 cfh | 137 cfh |
| 50% load | 161 cfh | 180 cfh |
| 75% load | 243 cfh | 238 cfh |
| 100% load | 281 cfh | 290 cfh |
For the smaller models, Kohler’s product pages give the half-load figure: 124 cfh for the 14RCA and 128 cfh for the 12RESV.
Turning cubic feet into something useful
Gas bills are often in therms. Kohler’s spec sheets use a nominal value of 1,000 Btu per cubic foot of natural gas, which makes the conversion easy: 100 cubic feet is about 1 therm.
- Take the half-load figure. For a 20RCA that is 161 cubic feet an hour.
- Divide by 100. That is about 1.6 therms an hour.
- Multiply by 24. That is roughly 39 therms for a full day of running at half load.
- Multiply by your gas rate. Your bill shows the price you pay per therm.
That is our own arithmetic from Kohler’s figures, and real use will be lower whenever the load is light. A home rarely sits at half load all day and all night.
The weekly exercise uses very little. At 71 cubic feet an hour, a 20-minute exercise burns about 24 cubic feet.
Gas Pressure, Meter and Pipe Size
This is the part that decides whether a natural gas generator runs well. It is also the part homeowners hear least about.
The pressure Kohler asks for
| Item | 20RCA | 26RCA |
|---|---|---|
| Natural gas supply pressure | 3.5 to 11 inches of water column | 3.5 to 11 inches of water column |
| Propane supply pressure | 7 to 11 inches of water column | 7 to 11 inches of water column |
| Fuel inlet size | 1/2 inch NPT | 3/4 inch NPT |
| Natural gas demand at full load | 281,000 Btu per hour | 290,000 Btu per hour |
“Inches of water column” is simply a unit for low gas pressures. Your installer measures it with a gauge called a manometer. The pressure has to stay inside that range while the generator is running at full load, not only when it is idle.
The pipe size Kohler recommends
A long, thin pipe starves the engine. Kohler gives minimum pipe sizes by distance.
| Length of pipe run | 20RCA | 26RCA |
|---|---|---|
| 25 feet | 1 inch | 1 inch |
| 50 feet | 1 inch | 1 1/4 inch |
| 100 feet | 1 1/4 inch | 1 1/4 inch |
| 150 feet | 1 1/4 inch | 1 1/4 inch |
| 200 feet | 1 1/4 inch | 1 1/2 inch |
These are Kohler’s minimum recommendations. Your gas fitter will size the pipe to local code and to everything else on the line.
The meter
Your gas meter has a maximum flow, printed on its rating plate. The generator’s demand is added to everything else that burns gas: the furnace, the water heater, the range and the dryer.
A 20RCA can ask for 281 cubic feet an hour by itself. If your meter cannot supply that on top of the other appliances, the gas company may need to fit a larger one. Ask about this before you sign for the generator, because it can affect both the schedule and the cost.
Tip: call the gas company early
Give your gas utility the generator’s full-load demand in Btu per hour and ask two questions. Can my meter handle it? Is my delivery pressure enough? Your installer can make the call for you, but it should happen before installation day.
Altitude and Heat Reduce the Rating
A gas engine makes less power in thin or hot air. Kohler’s spec sheets give two general rules for derating.
- Altitude: derate 4% for every 1,000 feet of elevation above 500 feet.
- Temperature: derate 2% for every 10 °F above 60 °F.
Here is what that can mean. Take a 20RCA on natural gas, rated at 18 kW. At 5,500 feet, the altitude rule takes off about 20%, which leaves roughly 14.4 kW. On a 90 °F day, the temperature rule takes off about 6% more.
So a mountain home on natural gas may get much less than the number on the brochure. If you live at altitude or in a hot climate, ask the dealer to show you the derated figure. Kohler says its liquid-cooled models are better suited to higher altitudes and hotter climates.
Natural Gas or Propane for a Kohler?
Most homes do not really choose. If you have gas service, you use it. If you do not, you use propane. When you do have a choice, this table helps.
| Point | Natural gas | Propane |
|---|---|---|
| Rating on a 20RCA | 18 kW | 20 kW |
| Rating on a 26RCA | 24 kW | 26 kW |
| Fuel supply | Continuous, from the utility | A tank that must be refilled |
| Fuel storage on site | None | A large tank |
| Supply pressure needed | 3.5 to 11 inches of water column | 7 to 11 inches of water column |
| Fuel use at half load, 20RCA | 161 cfh | 82 cfh, about 2.25 gallons an hour |
| Main thing to check | Meter capacity and pipe size | Tank size for the days you want to cover |
The propane figure in gallons is our arithmetic. Kohler’s sheet gives a conversion of about 36.4 cubic feet of propane vapor to the gallon.
The good news is that you are not locked in. Kohler’s spec sheets describe the fuel system as multi-fuel and field-convertible between natural gas and propane. If gas service reaches your street later, a dealer can convert the generator. It is not a job for an owner.
Our guide to whole-house generators compares the fuels in more depth.
What a Natural Gas Installation Involves
Kohler is blunt on this point. Its website says, “Installing a standby generator is not a DIY project.” It adds that certified installers handle local permits and coordinate licensed electricians and pipefitters.
A typical natural gas job has these stages.
- A free site visit. Kohler says its dealers assess your power needs and local permit requirements, then give a no-obligation quote.
- A gas check. The installer confirms the meter capacity, the delivery pressure and the pipe route.
- Permits. Electrical and gas permits are pulled. Kohler says its certified dealers manage this for you.
- Placement. Kohler’s spec sheet says the aluminum enclosure allows installation as close as 18 inches from the home. Local code still decides the final position.
- Gas piping. A licensed gas fitter runs a line of the right size, with a shutoff valve, to the generator.
- The transfer switch. An electrician fits the automatic transfer switch at your panel.
- Startup and testing. The dealer runs the generator under load and checks the gas pressure while it works.
Kohler’s FAQ lists three things that move the installed cost: the fuel source and whether it is already connected, local permit requirements, and where the generator sits on your property. A short gas run from a meter with spare capacity is the cheapest case. Still weighing a standby unit against a portable? Read portable vs standby generators.
Gas and electricity are not weekend projects
A natural gas leak can cause a fire or an explosion. A wiring mistake can send power back down the utility line. A generator placed in the wrong spot can let carbon monoxide into the house. Use a certified dealer or licensed trades, with permits and an inspection. Kohler also says authorized installation is important to keep your warranty valid.
Buying a Kohler for Natural Gas
Kohler sells mainly through certified dealers, and it also names online retailers, including Amazon. Its site says that if you buy online, you should then find a certified Kohler dealer to install the generator.
When we checked Amazon in October 2026, the current 20RCAL and 26RCAL packages showed third-party buying options only, with no standard buy button. You can still view the Kohler 20 kW package with a 200-amp transfer switch and the Kohler 26RCAL-200SELS to see what a full system includes.
These three Kohler products did have a normal listing with stock.
Complete 20 kW package
Kohler 20RESCL-200SELS 20 kW Standby Generator with 200-Amp Transfer Switch
A 20 kW air-cooled Kohler sold with a 200-amp, service-entrance rated transfer switch that includes load shedding. It is from the RES generation that came before today’s RCA models.
- Size20,000 watts
- Transfer switch200 amps, service entrance rated
- Load sheddingIncluded
- Response time10 seconds
- Warranty5-year / 2,000-hour limited
- Weight500 lb
- Why it works: it is a matched generator and switch, so the load-shedding feature can hold back big appliances when the generator is busy.
- Who it is best for: homes with 200-amp service that want one package, and are comfortable with the earlier model generation.
- What it solves: corrosion. The listing describes the enclosure as 100% corrosion-proof, which matters near the coast.
- Handy extras: the listing gives the size as 48 by 26.2 by 29 inches and the battery as Group 51, bought separately.
- Keep in mind: this is an earlier generation than the 20RCA. Ask the seller for the spec sheet and confirm its natural gas rating and gas pressure range before you buy. Only two were in stock when we checked.
As an Amazon Associate we earn from qualifying purchases. Specs come from the Amazon listing, checked October 2026.
Service kit, 17 to 20 kW
Kohler Maintenance Kit for CH1000 Generators (17, 18 and 20 kW)
Kohler’s own service kit for 17, 18 and 20 kW generators with the CH1000 engine. The 20RCA uses a CH1000 engine and is rated at 18 kW on natural gas.
- Fits17, 18 and 20 kW models
- EngineKohler CH1000
- Air filterIncluded
- Oil filterIncluded
- OilCorrect amount included
- Weight7.64 lb
- Why it works: it puts the filters and the right quantity of oil in one box, so there is no guessing over part numbers.
- Who it is best for: owners who are comfortable doing a basic service, or who want the right parts ready for a technician.
- What it solves: missed maintenance, which Kohler says can affect long-term reliability and warranty standards.
- Handy extras: the listing says it promotes easy starting and helps prevent costly repairs.
- Keep in mind: check your engine model before ordering. A generator still needs a professional inspection of the gas and electrical side.
As an Amazon Associate we earn from qualifying purchases. Specs come from the Amazon listing, checked October 2026.
Service kit, 12 and 14 kW
Kohler GM62346-SKP1-QS Maintenance Kit for 12/14 kW Residential Generators
The matching Kohler service kit for its smaller residential generators.
- Fits12 and 14 kW residential models
- Part numberGM62346-SKP1-QS
- Air filterIncluded
- Oil filterIncluded
- OilCorrect amount included
- BrandKohler
- Why it works: it is the manufacturer’s own kit, with the recommended filters for these engines.
- Who it is best for: owners of 12 and 14 kW Kohler home generators.
- What it solves: the yearly service. Having the kit on the shelf means it gets done on time.
- Handy extras: the listing says it includes everything needed for regular maintenance.
- Keep in mind: confirm the fit against your model and serial number. Kohler’s site recommends 5W-30 full synthetic oil and says not to mix oil types.
As an Amazon Associate we earn from qualifying purchases. Specs come from the Amazon listing, checked October 2026.
Running a Kohler on Natural Gas Through a Long Outage
Natural gas removes the refueling job, but the engine still needs watching.
- Check the oil. Kohler recommends checking the oil level after every 8 to 24 hours of operation, depending on the size and model.
- Shut down properly to check it. Kohler’s steps are to switch the generator’s breaker off, let it run with no load for 2 to 5 minutes, press OFF, then wait 2 minutes before reading the dipstick.
- Use the right oil. Kohler says its generators ship with 5W-30 full synthetic oil and that synthetic and conventional oils should not be mixed.
- Let it exercise between outages. The 26RCA spec sheet lists weekly, bi-weekly and monthly exercise settings.
- Keep snow and debris clear of the enclosure and the gas meter.
In cold regions, Kohler recommends cold weather accessories when temperatures drop below 32 °F. Ask your dealer which ones suit your model. Our emergency power outage checklist covers the rest of an outage plan.
Common Mistakes With Natural Gas Generators (and the Fix)
Pro Tips for a Natural Gas Kohler
- Write down the Btu figure. For a 20RCA it is 281,000 Btu per hour on natural gas. Every gas professional you speak to will ask for it.
- Ask about load shedding. A transfer switch with load management helps most on natural gas, where the rating is lower.
- Keep the gas run short. A generator placed near the meter needs less pipe and loses less pressure.
- Photograph the meter’s rating plate and send it to the installer before the site visit.
- Ask for the startup report. It should show the gas pressure measured under load.
- Plan one service a year. Kohler says a comprehensive service typically includes a full inspection, oil and air filter replacement, battery testing and a transfer switch check.
Real-Life Scenarios: Does Natural Gas Fit?
These are typical situations that buyers describe in forums and reviews. They are examples to help you plan, not quotes from real people.
🏘️ The suburban home
You have gas heat, a gas water heater and a gas range, and the meter is on the side wall by the driveway.
A natural gas Kohler is the obvious fit. The question is whether the meter can supply one more large appliance.
Next step: have the meter and pressure checked
⛰️ The mountain home
You live at 6,000 feet and want a 20RCA to run the whole house on natural gas.
Altitude takes a large slice off the rating, so the generator may be smaller than you think.
Next step: ask for the derated figure, or look at a larger model
🌾 The rural home
There is no gas main on your road, but you already have a propane tank for heating.
Propane is your fuel, and you get the full rating. The tank size becomes the thing to plan.
Next step: size the tank with your propane supplier
Kohler Natural Gas Home Generators: FAQ
Do Kohler home generators run on natural gas?
Yes. Kohler says its standby generators run on either natural gas or liquid propane and connect directly to your existing natural gas line or to a propane tank on your property.
How much natural gas does a Kohler 20 kW generator use?
Kohler's spec sheet for the 20RCA lists 161 cubic feet an hour at half load and 281 cubic feet an hour at full load. During its weekly exercise it uses about 71 cubic feet an hour.
What gas pressure does a Kohler generator need?
The spec sheets for the 20RCA and 26RCA ask for a natural gas supply pressure of 3.5 to 11 inches of water column. For propane the range is 7 to 11 inches. An installer measures it with the generator running.
Is a Kohler generator less powerful on natural gas?
Most models are. The 20RCA is rated at 20 kW on propane and 18 kW on natural gas. The 26RCA is rated at 26 kW on propane and 24 kW on natural gas.
What size gas line does a Kohler generator need?
Kohler's minimum recommendation for the 20RCA on natural gas is 1 inch pipe for runs up to 50 feet and 1 1/4 inch pipe for 100 to 200 feet. The 26RCA needs 1 1/4 inch pipe from 50 feet and 1 1/2 inch at 200 feet. Your gas fitter makes the final call.
Can a Kohler generator be converted from propane to natural gas?
Yes. Kohler's spec sheets describe the fuel system as multi-fuel and field-convertible between propane and natural gas. The conversion should be done by a Kohler dealer.
Your Natural Gas Generator Checklist
- Confirm your home has natural gas service and find the meter.
- Note the meter’s capacity from its rating plate.
- List your other gas appliances.
- Choose a size using the natural gas rating.
- Write down the generator’s full-load demand in Btu per hour.
- Ask the gas company about meter capacity and delivery pressure.
- Have a certified dealer measure the pipe run and size the line.
- Apply the altitude and temperature rules if they affect you.
- Let the dealer handle permits and inspection.
- Ask for the gas pressure reading under load at startup.
The bottom line
A Kohler on natural gas gives you backup power with no refueling, as long as the gas supply is sized for it. Size on the natural gas rating, check the meter and the pipe, and let a certified dealer do the work.
As an Amazon Associate we earn from qualifying purchases.
Sources: Kohler’s official home generator website (kohlerhomeenergy.rehlko.com): the home page, the product pages for the 12RESV, 14RCA, 20RCA, 26RCA, 24RCLA and 48RCLC, the FAQ, the online retailers page and the service and maintenance page; Kohler specification sheets G4-272 (20RCA) and G4-315 (26RCA); Amazon listings for the products named in this guide. All checked October 2026.
