When a pipe fails, the fastest way to limit the damage is to stop the water at the source. That only works if you already know where the main shutoff is, everyone in the house knows too, and the valve turns.
Finding it takes about ten minutes on an ordinary afternoon. Nobody does it, which is exactly why it is worth doing. This page is general information, not a repair guide. If water is actively coming through a ceiling or a wall, or you smell gas or see sparks, treat that as an emergency and call the right professional.
Where the main shutoff usually is
Near the water meter
- What you are looking for
- A valve on the pipe just before or after the meter
Where the line enters the house
- What you are looking for
- A valve where the pipe comes through the foundation or the floor
Basement or crawlspace
- What you are looking for
- Often on the wall closest to the street
An outside box
- What you are looking for
- A ground-level box near the street or the foundation, sometimes with a curb valve inside
| Where to look | What you are looking for |
|---|---|
| Near the water meter | A valve on the pipe just before or after the meter |
| Where the line enters the house | A valve where the pipe comes through the foundation or the floor |
| Basement or crawlspace | Often on the wall closest to the street |
| An outside box | A ground-level box near the street or the foundation, sometimes with a curb valve inside |
Two kinds of valve
- Usually a gate valve
- Turns several times
- Often stiff if unused for years
- May need gentle, steady effort
- Usually a ball valve
- Turns a quarter turn
- Closed when the lever sits across the pipe
- Easier to check at a glance
Wheel or round handle
- Usually a gate valve
- Turns several times
- Often stiff if unused for years
- May need gentle, steady effort
Lever handle
- Usually a ball valve
- Turns a quarter turn
- Closed when the lever sits across the pipe
- Easier to check at a glance
The ten minute check
6 things to do
Ticks are for this visit only. Nothing here is saved anywhere.
Keep it turning
A valve you never touch can seize. Some people turn the main shutoff off and on once a year, gently, to keep it free. Home Base has a yearly job for exactly this, called Turn the valve to keep it free. If yours does not move, stop and ask a plumber, because forcing it can break it.
Also note the smaller shutoffs: the ones under the sinks and behind the toilets. Those are a quick way to stop a single leak without shutting off the whole house.
Write it where anyone can find it
The most useful page in a home binder is the one titled if something goes wrong tonight: where the water, gas and electricity shut off, which way each turns, and who to call first. Fill in the water line today. For the gas and the electrical panel, note where they are and leave the operating to a qualified person. If you are starting a binder, see what goes in a home binder.