Find it before you need it
The time to find your main shutoff is on a quiet afternoon, not while water is coming through a ceiling. Take five minutes now to locate it, check that it turns, and show everyone in the house where it is. A tag on the valve and a note on the inside of the utility room door help visitors, sitters and tenants.
Where the main shutoff usually is
In most Pennsylvania houses, the water service line comes through the foundation wall facing the street and enters the basement at or below floor level. The main shutoff is usually within a few feet of where the pipe comes in, either just before or just after the water meter.
Look:
- On the basement wall facing the street, near the floor.
- Next to the water meter. There are often valves on both sides of the meter; the one on the house side is the one to use.
- In a crawl space in houses without a full basement, near the front foundation wall.
- In a utility closet or garage in slab-on-grade houses and some townhouses, often near the water heater.
- In the front-room wall or under the stairs in some older rowhomes, where the line enters below the front of the house.
If you can’t find it, follow the largest pipe coming through the foundation, or ask a plumber to show you on the next visit.
The curb stop
There is also a valve outside, usually near the property line or sidewalk under a small metal cover, called the curb stop. It belongs to or is controlled by the water utility in most areas, and often needs a special key. Don’t rely on it in an emergency; call your utility if the inside valve fails. Some utilities, such as Capital Region Water, explain which parts of the service line the owner is responsible for on their websites.
How to close each type of valve
Gate valve (round wheel handle)
Common in older houses. Turn the wheel clockwise until it stops. It may take many turns. Don’t force it hard: old gate valves can break internally, leaving the gate stuck partly open, or the stem can start leaking. If it won’t close fully, close it as far as it goes and call your water utility about the curb stop.
Ball valve (lever handle)
Common in newer installations and repairs. Turn the lever a quarter turn so it sits across the pipe instead of along it. Ball valves are faster and more reliable in an emergency, which is why replacing an old main gate valve with a full-port ball valve is one of the most useful small upgrades in an older house.
Fixture valves (small oval handles)
Under sinks and behind toilets. Turn clockwise to close. These are useful for a leak at a single fixture, so you can keep water on elsewhere. Older ones often won’t turn or begin to drip after being moved; if so, close the main instead. See faucet and fixture repair.
Shutting off the water heater
If the water heater is leaking:
- Close the cold-water inlet valve on the pipe going into the top of the heater.
- Turn off the energy supply. For gas, turn the gas control to “off” or “pilot.” For electric, switch off the heater’s breaker.
- Don’t open the drain valve unless a plumber has asked you to; the water inside is hot.
Our water heater repair page explains how to tell a tank leak from a fitting or valve leak.
After you close the main
- Open a faucet on the lowest floor to drain the pipes and relieve pressure, which reduces the water still flowing from a burst.
- Turn off the water heater if the water will be off for long, so a gas or electric heater doesn’t run with no water coming in.
- Move valuables and turn off electricity to wet areas if it is safe to reach the panel.
- Call a plumber. Describe what burst and where. See emergency plumbing.
Turning the water back on
Open the main slowly. Opening it quickly sends a surge through the pipes that can loosen sediment and stress old joints. Open a few faucets to let air out, starting with the lowest ones. Expect sputtering and some discoloured water for a minute or two. Check the repair for drips once the system is under pressure.
When the valve won’t move
- Don’t use a long wrench or hammer on it. Breaking an old valve with the water on can make the emergency worse.
- Call your water utility. Many can shut off the curb stop for you, and some have emergency lines for exactly this.
- Have the valve replaced afterwards. A plumber can replace the main shutoff, usually by having the utility turn off the curb stop for the duration.
Appliance and outdoor valves
Many leaks start at an appliance rather than a pipe. Knowing these valves lets you stop a leak without shutting off the whole house:
- Washing machine: two valves (hot and cold) on the wall behind the machine. Close both. Rubber hoses that are bulging or cracked should be replaced with braided stainless hoses.
- Dishwasher: usually a small valve under the kitchen sink on the hot-water line.
- Refrigerator ice maker: a small valve on the thin supply line, often under the sink or in the basement below the kitchen.
- Toilet: the oval valve on the wall or floor behind it; see toilet repair if it won’t close.
- Outdoor faucets: an inside valve on the line feeding each hose bib, usually in the basement on the wall nearest the faucet.
Make an emergency card
Write a short card and tape it inside the utility room door or near the water heater:
- Where the main shutoff is, and which way to turn it.
- Where the water heater’s inlet valve and gas or breaker switch are.
- Your water utility’s phone number, from your bill.
- Your gas utility’s emergency number.
- The phone number for a plumber.
It takes ten minutes and makes the first minute of any emergency calmer, especially for older relatives, babysitters and tenants.
Winter checks
In a Pennsylvania winter, a split pipe on an outside wall or in a crawl space is the most common reason for a sudden shutoff. Before cold weather:
- Disconnect hoses and close the inside valve for each outdoor faucet, then open the outside tap to drain it.
- Know which valves control pipes in unheated spaces.
- If you will be away, consider closing the main and draining the system, or keep the heat on and ask someone to check the house.
Our page on burst and frozen pipe repair covers prevention in more detail, and leak detection explains how to check for a hidden leak afterwards.
Shutoff questions
Which way do I turn to shut off the water?
Clockwise for round-handle valves. For a lever, a quarter turn so it sits across the pipe.
Where is the main shutoff in a rowhome?
Usually where the service line enters the basement on the street side, near the meter.
Can I use the curb stop myself?
It is usually controlled by the utility and needs a special key. Call the utility instead.
My main valve leaks after I turned it. What now?
Close it fully if you can, put a container under the drip and ask a plumber to replace it.
Should I replace an old gate valve?
Yes, if it is stiff or doesn’t close fully. A full-port ball valve is quicker and more reliable. See how calls work if you want us to connect you with a plumber.