There are several reasons why you may 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 the gas off to do so. Still, there are more important—and more urgent—reasons you may need to do this. If you smell gas in the vicinity of your water heater—or anywhere in your house, for that matter—you should turn off the gas to the water heater immediately.
The smell of gas alerts you to a potential gas leak that needs to be located and repaired immediately. Natural gas is odorless, but utility companies include an additive that smells like rotten eggs so that consumers can easily detect the presence of a gas leak. If left unattended, a gas leak can lead to an explosion or fire.
If the gas smell is strong, leave the house immediately and call the gas utility company. However, if the gas smell is very faint, it's a good idea to shut off the gas to any flame-operated appliances in your home, including your gas water heater. After that, you can call the utility company and request that they come to 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, it's not just a gas leak in or around the water heater that prompts you to shut off the gas. Any gas leak, anywhere in the house, could potentially be detonated by the open flame on your water heater.
Equipment / Tools
- Flashlight (if needed)
- Cell phone
- Gas leak detector (optional)
Follow this quick process for shutting off the gas to your water heater, whether for routine repairs and maintenance or as an emergency measure if you smell gas in the house.
Clear Around the Water Heater
Move any items away from the area around the water heater so you can access the gas pipe and shutoff valve. Having the area cleared out will also help the gas company quickly review the situation if they are checking for leaks.
Locate the Gas Pipe
Find the gas pipe that feeds gas into your water heater and locate the shutoff valve. This is not the valve located on the control box mounted on the water heater but instead, a valve installed along the pipe run itself. The valve may appear differently 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 your water heater is old or was installed by an amateur), the shutoff valve may be absent or may be located some distance away from the water heater. To find it, follow the gas pipe back from the water heater burner until you find the valve. In the event you find no shutoff valve at all, your only option will be to turn off the main gas valve at the gas meter.
Shut Off the Gas Valve
Rotate the handle of the shutoff valve 1/4 turn until it stops. When turned off, the handle should be at a 90-degree angle to the pathway of the pipe itself; a handle parallel to the pipe indicates an open valve.
Additionally, you should 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 has not ignited.
Contact a Professional
If you suspect a gas leak, immediately call your gas company to investigate the source 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, a utility technician will find a fairly simple cause for a gas leak, such as a small gap in a connection between pipe segments or where a flex tube is connected to the gas pipe. It may take only minutes for the problem to be remedied, and the solution 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, technicians will likely use an electronic sensing wand to check for the presence of gas around each joint and identify which 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 built-in shelving, but these areas should always remain empty to make for easy access and proper safety precautions. Additionally, water heaters need proper ventilation as a fire prevention measure.
- Never store combustibles such as paints, chemicals, or solvents on or near your water heater.