How to Turn off the Gas to Your Water Heater

Hot water heater maintenance
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  • Working Time: 15 mins
  • Skill Level: Beginner

There are several reasons why you might need to turn off the gas supply to your water heater. For example, if you are planning to replace a water heater, you will need to turn off the gas. But there is a more important and more urgent reason you may need to do this: If you smell gas in the vicinity of your water heater—or anywhere in the house, for that matter—then you should turn off the gas to the water heater immediately. 

Beware of Gas Leaks

The smell of gas alerts you to a potential gas leak that needs to be located and repaired. Natural gas is naturally odorless, but utility companies include an additive that smells like rotten eggs so that consumers can easily detect a gas leak. Left unattended, a gas leak can lead to an explosion and fire. Utility CenterPoint Energy's description of how to handle a gas leak indicates how serious a gas leak can be:

  1. Leave immediately on foot! Do not use electric switches, telephones (including cell phones), drive, or start a car or anything that could cause a spark.
  2. Go directly to a safe location, on foot, and call both CenterPoint Energy and 911. Do not use e-mail or the Internet to contact the company about a leak, and never assume someone else has reported the leak.
  3. Alert your neighbors. CenterPoint Energy checks suspected natural gas leaks at no cost to you.
  4. Never try to repair a natural gas leak yourself. Leave all repairs to a trained technician.

If the gas smell is strong, you should follow this advice precisely: Leave the house immediately and call the gas utility company, because there is imminent danger. However, if the gas smell is very faint, it is a good idea to shut off the gas to flame-operated appliances, including your gas water heater. After that, you can call the gas utility company and request that they come and locate and repair the leak. Normally this is a free service, and you can count on the utility service being there very, very quickly. The gas companies understand the potential danger of gas leaks, and they are very diligent about addressing them. 

Remember that it is not just a gas leak in or around the water heater that prompts you to shut off the gas to the water heater. Any gas leak, anywhere in the house, could potentially be detonated by the open flame on your water heater. 

What You'll Need

Equipment / Tools

  • Flashlight (if needed)
  • Telephone


Follow this process for shutting off the gas to your water heater, whether for routine repairs or maintenance, or as an emergency measure if you smell gas in the house.

  1. Clear the Area Around the Water Heater

    Move any items away from the area around the water heater so you can access the gas pipe and shut-off valve. Having the area cleared out will also help the gas company quickly review the situation if they are checking for gas leaks.

  2. Locate the Gas Pipe

    Locate the gas pipe that feeds gas into the water heater, and locate the shut-off valve. This is not the valve located on the control box mounted on the water heater but is instead a valve installed along the pipe run itself. The valve can have different appearances depending on who did the installation and when it was installed. Most plumbers install a lever- or knob-operated shutoff valve located within a few feet of the water heater control box.


    In rare instances, and particularly if the water heater is an old installation or was installed by an amateur, the shutoff valve may absent or may be located some distance from the water heater. Follow the gas pipe back from the water heater burner until you find the valve. In the event you find no shut-off valve at all, your only option will be to turn off the main gas valve at the gas meter. 

  3. Shut Off the Gas Valve

    Turn the handle of the shut-off valve one-quarter turn until it stops. When it is turned off, the handle will be at a 90-degree angle to the pathway of the pipe itself; a handle parallel to the pipe indicates an open valve.

    Check to make sure that the water heater has turned off. To do this, turn up the temperature setting on the control box, then peek inside the access hatch at the bottom of the water heater to make sure the burner is not ignited.

  4. Call the Gas Company

    If you suspect a gas leak, immediately call the gas company to investigate the source of the leak and repair it. Again, this is a free service from the gas utility company.

    If you still smell gas despite turning off the water heater, shut off the gas at the meter and call the gas company.

Where Gas Leaks Occur

In most instances, the gas company technician will find a fairly simple cause for the gas leak, such as a small leak in a connection between pipe segments or in the connection where a flex tube is connected to the gas pipe. It may take only minutes for the problem to be remedied, as it can be as simple as tightening the connections.

An old standby technique for checking gas pipe joints for leaks is to coat the joints with a soap-and-water mixture and look for bubbles. These days, the technician will likely use an electronic sensing wand to check for the presence of gas around each joint and identify which one needs to be tightened or replaced. The technician should relight the water heater for you after completing the repair. 

Water Heater Safety Tips

  • Keep the area around the water heater clear. Many people use the flat top of the water heater for storage or build in shelving around the water heater, but these areas should be kept clear. The water heater needs proper ventilation as a fire prevention measure.
  • Never store combustibles such as paints or solvents on or near the water heater.