The main water shut-off valve is the most important plumbing fixture in your house, and the one most people can't find when they need it. Knowing where it is and that it works turns a burst pipe from a flood into a mess. Here's how to find yours, how to use it and what to do if it's stuck. For other plumbing help, visit our page on plumbers in Portland, ME.
Where to look
- Homes with a basement: on the wall where the water line comes through the foundation, usually the side facing the street, near the water meter.
- Homes without a basement: in a utility room, a crawl space, near the water heater or where the line enters the house.
- Condos and apartments: your unit may have its own valve in a closet, under a sink or near the water heater, while the building's main is in a mechanical room.
There's usually also a valve at the street, often called a curb stop. In many systems it belongs to the water utility and needs a special key, so call the utility if you need it closed.
How to turn it off
| Valve type | What it looks like | How to close it |
|---|---|---|
| Gate valve | A round wheel handle | Turn clockwise until it stops. It may take several turns. |
| Ball valve | A straight lever | Turn a quarter turn so the lever sits across the pipe. |
Once it's closed, open a faucet on the lowest floor to drain the lines and confirm the water has stopped.
Test it before you need it
Once a year, close the valve and open a faucet to make sure the water stops, then open the valve again. Valves that haven't moved in years, which is common in older Portland homes, can seize or start leaking at the stem when finally turned. If yours won't move, don't force it with a wrench. Call a plumber to replace it. That's a small job compared with being unable to stop a burst pipe.
Fixture shut-offs worth knowing
- Toilets: a small valve on the wall behind the toilet. See toilet repair.
- Sinks: two valves under the sink, hot and cold. See faucet repair.
- Water heater: a valve on the cold-water line going into the heater.
- Washing machine: two valves on the wall behind it.
Label the main valve with a tag so anyone in the house can find it in an emergency.
When the water won't stop
If the main valve won't close or water keeps coming after it's closed, call your water utility about the curb stop and call a plumber right away. Read what to do about a burst pipe for the rest of the first 30 minutes.