How Do I Turn Off My Water Heater's Gas Supply?

Lauren Hamer
Written by Lauren Hamer
Updated May 6, 2022
Man fixing water heater
Photo: Minerva Studio / Shutterstock

Turning off the gas supply to a water heater can easily be done by following just six simple steps

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If you have noticed a gas-like smell near your water heater, your home could be experiencing a gas leak. You should turn off the gas supply as soon as you can. Luckily, this process is simple and you can tackle it in 10 to 20 minutes by using just your hands and some simple household tools.

  • Project Difficulty: 1 out of 5

  • Time Needed: 10 to 20 minutes, depending on the location of your gas valve and gas meter

  • Tools and Materials Required: Flashlight, cell phone, wrench, gas leak detector (optional)

Illustration depicting the valves and lines leading to a water heater

How to Turn Off a Gas Water Heater in 6 Quick Steps

Follow these simple steps to turn off the gas supply to your water heater.

1. Call 911 if You Suspect a Leak

The danger of a gas leak cannot be overstated. If you smell gas, the best thing to do is to step away from your home, call 911 or your gas company’s emergency line, and follow their instructions. After you are given the go ahead to re-enter your space, you can follow the below steps to shut off the gas to your water heater.

2. Find Your Water Heater

You should start by locating your actual water heater. The location of the water heater will differ depending on the design of your home, but they tend to be tucked away in a garage, basement, crawlspace, or attic. 

Occasionally, water heaters sit in a dedicated furnace closet. If you are having trouble finding it, just dig up the floorplans to your home. These plans should show the exact location of the water heater. You were likely given these plans upon the purchase of your home and your real estate agent should still have a copy even if you have misplaced them.

3. Clear the Area 

Once located, take some time to clear the immediate area of debris and clutter. This will allow a contractor to quickly assess the situation and come up with a game plan. Clearing an easy-to-navigate path to the water heater could end up reducing the cost of a gas valve replacement or getting new gas pipes installed.

4. Locate the Shut-off Valve 

Have your flashlight or cell phone handy to help you locate the shut-off valve. All gas appliances have a separate shut-off valve, typically within a few feet of the device. To find the gas shut-off valve on your water heater, look for a single handle, which you’ll usually find at the bottom of the unit.

5. Turn Off the Gas Supply 

To turn off the gas, turn the valve clockwise. If the valve is stuck, you may need to lodge it loose with a wrench. If you can’t get the gas valve to turn or can’t find the gas valve, then you may need to turn off the gas to the whole house. Also, keep in mind that you may have to reignite the pilot light once the issue has been diagnosed and fixed. 

6. Make Sure the Water Heater is Turned Off

You should look to see that the water heater has successfully been turned off. To do this, turn up the temperature setting on the heater’s control box. Open up the access hatch and look inside for the burner. If it has not ignited, you are good to go.

Man turning off water heater
Photo: Minerva Studio / Shutterstock

How to Turn Off Gas to the Whole House

Sometimes old water heaters lack a shut-off valve, or the valve is not near the heater. If you have been unsuccessful in stopping the gas supply to your water heater, here are the steps to turning off the gas to the entire home.

1. Find the Gas Meter

Your home should have a gas meter somewhere outside. You can usually find it on the front or side of your house. In rare cases, it could be inside of an enclosure attached to the outside of the building. If you are having trouble finding the meter, do not hesitate to call your local gas company. 

2. Locate the Gas Meter Shut-off Valve

Once you have found the gas meter itself, it is time to locate its shut-off valve. Don’t worry: In most cases, this valve is directly next to the gas meter itself. Scan the immediate vicinity until you spot the valve. Look for a ball valve attached to a black iron pipe, though designs may vary. If you live in a multi-unit building, each unit should have its own shut-off valve.

3. Turn Off the Gas Supply to the Home

Most gas valves require a wrench to open or close them, so now is the time to grab your wrench. The gas valve is on when it’s parallel to the incoming gas line. To stop the flow of gas, you need to give the valve a quarter-turn so that it is perpendicular to the gas line. Once completed, the gas line is closed, and the flow of gas stops.

4. Contact a Professional

Shutting the gas supply to your home will buy you some time and eliminate any immediate danger. But you should still hire a plumber to fix your gas lines as soon as you can. They will be able to determine the cause of the gaseous odor and make the necessary repairs. The typical cost to install or repair a gas line will range from $250 to $825.

DIY vs. Hiring a Pro to Turn off a Water Heater’s Gas Supply

You can turn off the water heater’s gas supply yourself if you suspect you have a gas leak and want to take a pre-emptive step. Hiring a professional plumber will cost anywhere from $45 to $200 an hour, and most professionals will charge you an hour’s work even if the job takes half that long. Turning off the gas yourself should cost $0, provided you have the right tools on hand. 

Gas leaks are a serious problem, however, and turning off the gas should only be your first step. It will minimize the risk of gas inhalation, but the leak itself must be addressed for safety’s sake. If you suspect a gas leak, you should call 911 and contact a local gas plumber to diagnose and correct the issue. 

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