How To Shut Off Your Water Main (Before You Need To)

Do this now, not during the emergency

Every emergency call we take begins the same way: we ask whether the water is off, and the homeowner does not know where the valve is. Finding it under pressure, in the dark, with water spreading, costs minutes that cost money.

This is a ten-minute task on a normal afternoon. Do it once and never worry about it again.

Where the main shut-off valve usually is

• Basement homes: on the wall facing the street, often near the water heater or the front foundation wall
• Crawlspace homes: just inside the crawl access, where the service line penetrates the foundation
• Slab-on-grade homes: in the garage, a utility closet, or near the water heater
• Townhomes and condos: in a utility closet, mechanical room, or behind an access panel — sometimes shared, so ask the HOA
• All homes: a curb-stop valve in the meter box near the street or sidewalk as a backup

The two valve types and how each closes

A gate valve has a round wheel handle. It closes by turning clockwise through several full rotations until it stops. These are common in older homes and they seize when they are never exercised, which is exactly why we recommend turning yours once a year.

A ball valve has a lever handle. It closes with a single quarter turn until the handle sits perpendicular to the pipe. When the handle is parallel to the pipe, the valve is open. These are more reliable and are what we install when replacing a failed main valve.

If the valve will not turn

Do not apply extreme force to a wheel-handle valve. The stems on old gate valves snap, and a snapped stem in an open valve means you now cannot shut the water off at all.

Go to the curb stop instead. The meter box near the street has a lid you can lift, and inside is a valve that closes with a meter key — a long T-handled tool available at any hardware store. Buy one now and keep it with the shut-off location noted.

If the main valve is seized, have it replaced during normal business hours. It is inexpensive planned work and it is the single most important valve in the house.

After the water is off

Open the lowest faucet in the house to drain remaining pressure downward, then open an upper faucet to let air in behind it. This empties the system faster and reduces how much more water reaches a leak.

Remember that a gas or electric water heater should be switched off if the house will be without water for any extended period, so the unit does not fire on an emptying tank.

The rest of the shut-off map worth knowing

• Individual fixture stops under every sink and behind every toilet — often enough to isolate a problem without killing the whole house
• The cold inlet valve on top of the water heater
• The hose bib supply valves inside the wall, which should be closed before winter
• The gas shut-off at the meter and at each gas appliance
• The main electrical breaker, in case water reaches wiring

Label it and tell the household

Tie a bright tag to the valve, write down the location, and make sure everyone in the house who might be home alone knows where it is and which way it turns. A teenager who can close the main valve is worth more in a burst-pipe scenario than the fastest plumber in the county.

If you cannot locate your shut-off at all, we will find it during any service visit and show you. It takes two minutes and it is the most useful two minutes of the appointment.