The water shut off valve behind a toilet.

Water Shut Off Valve

Originally contributed by • last updated 2/22/2021

Tony Webster CC-BY-SA-2.0

If you suddenly had to deal with a toilet overflowing, would you know how to shut off the water before you were up the proverbial creek without a paddle? If not, you’re probably going to want to learn how to find and use the water shut off valve for the toilet water supply line.


The term water shut off valve can refer to any of several water valves located throughout a home (or building) that open and close to allow or stop the flow of water. While the main water shut off valve controls the flow of water into the house, additional shut off valves, such as the toilet shut off valve or the washing machine valve, control the flow of water to individual faucets and appliances. Water valves can come in many different shapes, sizes, and materials, and selecting one is often determined by variables such as water pressure, connection type, and location along the water supply line.

What Does A Water Shut Off Valve Look Like?

One of the most important things a homeowner can know is how to identify and operate the main water shut off valve. But it’s just as important to be able to identify and operate secondary shut off valves, like the toilet shut off valve:

  • The main water shut off valve is most commonly located in the basement, crawl space, or utility room on the side of the house closest to the street. The water valve handle typically comes in two types: either a round handle or a blade style handle, both of which can be turned to allow or stop the flow of water into the home. The handles are sometimes painted red or have red plastic coverings.
  • It’s not always necessary to shut off the water at the main shut off valve. In many cases, individual faucets and appliances will have water shut off valves located near them, typically under them or behind them. This comes in handy to stop an overflowing toilet. In most cases, the valve handles are made of metal and are small and oval shaped. They are typically attached to a pipe or hose that leads to the fixture or appliance.