Why this valve matters more than anything else
When a pipe splits inside a wall or under a sink with no valve of its own, the only thing between you and a soaked floor is the house shutoff. Every minute water runs, it spreads under baseboards, into cabinets and through drywall. Closing the main stops that in seconds, and it does not depend on anyone arriving.
On many single-family homes in Fullerton, especially the postwar tract houses, the house valve is on the supply pipe where it rises out of the ground before entering the house. Common spots are near the front hose bib, along the wall facing the street, or inside the garage. There is a second valve in the meter box near the curb, but that one belongs to the city's water system and often needs a meter key.
Which valve do you have?
| Valve type | How it looks | How to close it | Watch out for |
|---|---|---|---|
| Gate valve | Round wheel handle, often brass | Turn clockwise until it stops, usually several full turns | Old gate valves can seize or break internally and may not seal fully |
| Ball valve | Straight lever handle | Quarter turn so the lever sits across the pipe | Lever in line with the pipe means open; across means closed |
| Meter box valve | At the curb, inside a concrete or plastic box | Usually needs a meter key; contact the city's water utility | This is the utility's side; do not force it or damage the meter |
Closing the main during a leak
Go to the house valve first
Head to the valve where the line enters the house rather than the street box. It is quicker and it is on your side of the system.
Turn it fully closed
Gate valve: clockwise until firm, without a wrench if you can avoid it. Ball valve: a quarter turn so the lever crosses the pipe.
Open a low faucet
Open a tub spout or a hose bib to drain the pressure left in the pipes. This slows the leak that is still trickling.
Turn off the water heater supply if hot water is leaking
Close the cold inlet on top of the tank and set a gas heater's control to off or pilot, or switch off the breaker for an electric unit.
Tell everyone in the house
Put a note on the kitchen faucet so nobody reopens anything before the repair.
If the valve will not cooperate
- IfThe wheel turns but water keeps flowingThe gate inside may be worn or broken. Leave it closed as far as it goes and contact the city's water utility about the curb valve.
- IfThe handle will not move at allDo not use a long cheater bar; old brass stems snap. Try steady hand pressure, then move on to the curb valve or wait for help.
- IfThe valve itself starts leaking when you turn itStop turning. A small drip at the packing nut is common on old valves; a plumber can repack or replace it.
- IfYou cannot find a house valve at allSome homes only have the curb valve. Ask a plumber to install an accessible house shutoff once the emergency is over.
What to ask a plumber about your shutoff
- Is my main a gate valve or ball valve, and is it in good condition?
- Would you recommend replacing it with a full-port ball valve, and why?
- Does replacing the main shutoff require a permit here? Check with the city if unsure.
- Are there fixtures in the house without their own shutoff valve?
Common questions
Can I use the curb valve in the meter box?
It is part of the city's water system and often needs a meter key. In a true emergency, contact the city's water utility. Avoid forcing it or damaging the meter.
Will closing the main affect my water heater?
The tank stays full but receives no new water. If you also drain hot water lines, turn the heater's gas control to pilot or switch off an electric unit so it does not heat an emptying tank.
How long can the main stay closed?
As long as needed. The house simply has no running water. Use bottled water and avoid flushing more than necessary until the repair.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.