Shutting off utilities, such as your home's water supply or electrical power, is fairly common—something you do whenever making a repair or upgrade. By contrast, shutting off your natural gas supply is something you may never have to do. Work on branch gas lines in a home is not safe for amateurs and should be left to plumbers or gas company technicians. But most gas companies allow homeowners to shut off the gas at their own meters and even provide instructions for doing this safely. If you have questions about shutting off your home's gas supply at the meter, contact your gas utility provider.
If there is a strong gas smell in your home, leave the house immediately and call the utility company from outside or from a neighbor's house. Do not attempt to shut off the gas supply at the meter or anywhere else. Even turning on a light switch can ignite a gas explosion inside a house. A strong gas odor indicates a leak, which must be checked out by a utility technician.
Reasons for Shutting Off the Gas
The main shutoff valve controlling your home's natural gas supply may come into play during major construction or renovation involving gas lines or when closing up or shuttering a home, to prevent possible flood damage. In rare instances, you may need to shut off the gas supply in the event of a natural disaster.
Once the valve is turned off, do not turn it back on by yourself. It must be turned on by a gas company technician. The gas company will likely perform a pressure test on the system and relight all pilot lights in the house as part of turning the gas back on.
Location of the Main Shutoff Valve
The main gas shutoff valve is located near the gas meter supplied by your utility company. Your gas meter may be located outside your home on an exterior wall, or it may be found inside your home on an outside wall—often in a basement or utility area, such as a garage or the mechanical room where the furnace or water heater are located.
Typically, the valve is located on the supply pipe that rises from the ground and ultimately connects to the meter. The valve appears in the line before the meter so that the gas can be shut off before it reaches the meter. There also may be a second shutoff valve after the meter, between the meter and the house. The correct valve to shut off is the one before the meter.
How to Shut Off the Main Gas Valve
The shutoff valve has a rectangular (or flat-sided) tab that is about 1/2 inch thick; this is what you turn to shut off the gas. When the tab is parallel to the gas pipe, the valve is open and the gas is on. When it is fully perpendicular to the pipe, the valve is closed and the gas is off.
To close the valve, use an adjustable wrench adjusted to fit snugly over the valve tab. You can also use clamping pliers or an open-end wrench. Turn the tab so it is fully perpendicular (90 degrees) to the gas line. It will take only a quarter-turn.
NOTE: Many gas meter valves have a hole in the tab (or on a bracket attached to the tab) that will line up with a corresponding hole in the valve body when the gas valve is in the closed position. The utility company will use the hole to lock the valve in a closed position when the gas account is closed. When the holes in the valve handle are lined up, it indicates the valve is in the off position.