What Size Gas Line For A Home Backup Generator?

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Most residential homes need a 1″ gas line to provide sufficient gas flow to your home backup generator to power appliances for an extended time. A 1″ gas line will deliver sufficient flow to most generators up to 30 feet from the meter.

If your generator is located farther than 30 feet from the gas meter, then you will need a larger line. A 1 1/4″ gas line is required from 30 to 120 feet. A 1 1/2″ gas line is required from 120 to 300 feet.

The gas volume and pressure from the main 1″, 1 1/4″ or 1 1/2″ line is reduced by the generator’s secondary regulator. The larger input line usually connects to a smaller 3/4″ yellow pipe, which has a regulator at the tank.

Correctly sizing the gas line from the meter ensures your backup generator can provide power efficiently for days or weeks, even at full draw.

A professional plumbing firm will be required to install the gas line for your new natural gas-powered generator. It will only take a few hours, and it will be the most affordable element of the generator installation.

Here are some gas lines we recommend:

1 Inch CTS Yellow Medium-Density Poly Pipe Line

Dormont 16100BP48 1″ Gas Hose

Highcraft GUHDZD3436Q 1″ Flexible Yellow Epoxy Coated Gas Line Connector

Your Generator Needs a Dedicated Gas Line

A natural gas-powered backup generator needs its own dedicated gas line that should be run directly from the meter. This ensures the generator has adequate gas supply, and is not under-sized because it’s sharing a line with other appliances like your heater and stove.

Simply tapping into an existing line does not account for the much higher gas consumption of a backup generator. The existing gas line will only be sized for your appliances, which means it will be undersized once you add the generator into it. The only reliable solution is to run a dedicated gas line to the backup generator so it has a constant gas supply in sufficient quantity.

Most generator manufacturers require a dedicated gas line under their product warranty terms. If you under-supply the generator with gas by using an existing shared line, the generator will have less electrical output, and could struggle to stay in it’s optimized power range for the electrical demand. The manufacturer will void the warranty if you use a shared gas line. Just another reason to use a dedicated line!

Cost To Run a Gas Line for a Home Backup Generator

Installing a natural gas pipe to a generator costs between $20 and $25 per foot. Running the gas line from your meter is one of the cheaper parts of the installation unless you’re more than 30 feet from the meter.

You can learn more about the cost to install a gas line for generator here. There are many factors that go into the cost of installing a gas line. Be sure to get bids from at least 2-3 plumbers to get the best price.

Related Questions and Answers

How do I get a gas line connected to my home backup generator?

A local gas distribution network operator is required to connect your home to a gas supply (DNO). Those that provide gas to your home are known as Distribution Network Operators (DNOs). The DNO installs the main line and gas meter. From there, you need to hire a plumbing company to install the dedicated gas line from your natural gas meter to your generator.

What size gas line do you need for a Generac generator?

Per Generac’s specifications, water columns at the generator intake should be 5 to 7 inches in diameter; less than 20 feet of gas line should be 1 inch, 20 feet through 130 feet should be 1.25″ gas line, and 130 feet through 305 feet should be 1.50″ gas line.

What gas pressure is needed for a Generac generator?

Liquid propane vapor requires a pressure of 10 to 12 in water column for Generac systems (19 to 22 mm Hg mercury). If you’re running your generator on natural gas, you’ll need to use various tables, sizes, and separations.

How much natural gas does a 22kw generator use?

When running at maximum power, a 22 KW Generac generator will use 9.7 cubic meters of natural gas. As long as the line is connected directly to your natural gas meter, it will keep your house functioning as long as the blackout lasts.

How many gallons of propane does a 22kw generator use per hour?

A 22kw generator uses as much as three and one-half gallons of propane per hour.

To find out more, see How Much Propane Does A Backup Generator Use?

What type of regulator do I need for a Generac generator?

Selecting a regulator that can handle around 9,000 cubic feet of gas per hour is essential. A 1-1/2″ Model 122-12 regulator with a blue spring and an upstream gas pressure of 2 psi would be the first option.

Can you hook up a portable generator to your house gas line?

Using a portable generator with natural gas is possible, but the process is not always straightforward. Natural gas may be used as a fuel source in certain portable generators, but in others, changes must be made.

You can learn more in How Do Home Backup Generators Work?

How far does a regulator have to be from a generator?

Vent openings for appliances with sealed combustion chambers and mechanical ventilation air intakes should be at least 5 feet away from the regulator safety relief valve (vent opening).

What Size Home Standby Generator Should I Get?

Choosing a home standby generator does not have to be difficult. This video should help:

But before you choose a size, you need to first answer this question: Do You Need a Home Backup Generator?

How many BTU does a natural gas generator use?

At 3600 RPM, a generator engine uses around 10,000 BTU per horsepower per hour when operating at full capacity.

How many BTUs does a 16kw Generac generator use?

For natural gas, the nominal fuel consumption is 247 cu ft/hr, while the nominal propane gas consumption is 110 cu ft/hr.

Can a gas regulator be installed upside down?

First, determine where and how to install your gas regulator. Some regulators may be installed in any orientation (including upside-down). Others can’t work until they’re installed according to the manufacturer’s instructions. In order to prevent the regulator from leaking, use a drip leg right in front of it.

Is it normal to smell gas by the meter?

A regulator on the gas meter allows you to fine-tune how much gas is delivered to your home or place of business. Occasionally, it may “burp” or “bleed” out a little quantity of gas in order to prevent the pressure in your house from being too high. A mild gas odor coming from the meter is, in fact, typical.

What is cheaper to run a gas or propane generator?

In terms of BTUs per cubic foot, natural gas gives 1,040, whereas propane delivers 2,490. As a result, you’ll use more than twice as much natural gas as you would propane in the same amount of time. That doesn’t mean propane is less expensive than natural gas. It’s a little more pricey.

Is a natural gas backup generator worth it?

Natural gas generators are more cost-effective, efficient, and environmentally friendly than fossil-fuel-powered generators. However, these generators aren’t the greatest option for every situation. It is up to the homeowner to decide what type matches their energy requirements and preferences.


The generator you are considering purchasing may require a gas line be connected. The size of this natural gas line depends on the distance and size of your generator. Make sure you check with the generator’s manufacturer’s recommendations and hire a professional plumber to run a dedicated line from the meter to your generator.

NEXT UP: Do I Need A Permit For A Home Backup Generator?

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Leon Ashcraft
About Leon Ashcraft

Leon Ashcraft is a Safety Instructor and consultant in Colorado with focus on OSHA, environmental health and safety, transportation safety, oil & gas, rescue operations and construction safety. Learn more about Leon here or connect with him on Twitter | LinkedIn | Medium