Start with how the house is built
Most older homes around Greenville, Anderson and Spartanburg sit on crawl spaces. In those houses the main valve is usually under the front of the house, a few feet inside the foundation wall where the service line comes in from the street. It is often a round gate valve handle or a lever on a short section of copper or PEX.
Slab homes, which are common in newer subdivisions around Simpsonville, Greer and Five Forks, usually put the valve in the garage near the water heater, in a utility closet, or behind an access panel in a laundry room.
Check the meter box next
Every home on public water has a meter, usually in a box near the street or sidewalk. Inside is a valve on the street side of the meter. It is meant for the utility, and it often needs a meter key to turn, but in an emergency it will stop the water to the whole house.
Homes on a well work differently
If your home uses a private well, there may be no meter at all. The quickest way to stop the water is to switch off the well pump breaker, then close the valve near the pressure tank. Many rural homes around Belton, Pickens and Travelers Rest have the tank in a small well house or in the crawl space.
What to do once you find it
Turn it slowly. Gate valves with round handles close clockwise and can take many turns. Lever valves close with a quarter turn so the lever sits across the pipe. Once it is closed, open a cold faucet at the lowest point of the house to drain pressure from the lines.
- Label the valve with a tag or bright tape
- Show everyone in the house where it is
- Clear storage away from it so it can be reached fast
- Test it once a year so it does not seize
If the valve will not turn
Do not force an old gate valve with a wrench. The stem can snap, leaving you with a valve that will not close or a new leak. Close the meter valve instead and call a plumber to replace the old valve with a quarter-turn ball valve in an easy-to-reach spot.
Questions readers ask
Is it safe to leave the water off overnight?
Yes, as long as you also turn the water heater to pilot or switch off its breaker so it does not heat an empty tank.
Should I turn the water off when I go on vacation?
It is a good habit, especially for longer trips or during cold weather. It limits the damage if a hose or fitting fails while you are away.
Sidney Treadway edits Homeowner Help for Plumbcraft Services, turning the questions our plumbers hear on calls into plain, practical articles for Upstate homeowners. About the editor