Why this valve matters more than anything else
When a pipe bursts, every minute the water runs adds to what has to be dried, cut out and replaced later. A plumber cannot get to you instantly, but you can stop the flow yourself in under a minute if you already know where the main shutoff is and that it turns.
On most Fullerton homes the house shutoff controls every fixture, the water heater and usually the irrigation. Closing it does not fix anything, but it turns an active flood into a contained problem you can deal with calmly.
Where to look on a Fullerton home
| Home type | Usual shutoff location | Notes |
|---|---|---|
| 1950s-70s slab tract home | Where the supply pipe rises out of the ground next to the house, often near the front hose bib or a front corner | Sometimes inside a small box or behind a shrub; follow the line from the meter toward the house |
| Home with attached garage | On the garage wall where the line enters, sometimes beside the water heater | Check for a second valve on the cold inlet of the water heater, which is not the main |
| Older home near downtown | At the foundation where the line enters, or under a raised floor | Valves here can be very old gate valves that stick |
| Condo or townhome | Inside the unit near the water heater or a utility closet, or a shared valve controlled by the association | Ask the association where your unit's shutoff is before you need it |
| Any home | Curb valve inside the water meter box near the street | Usually needs a meter key; this is the backup when the house valve fails |
Closing the main, step by step
Do this as soon as you see water where it should not be.
- Identify the valve type.A round wheel handle is a gate valve. A straight lever is a ball valve. They close differently, so look before you force anything.
- Close it fully.Turn a wheel handle clockwise until it stops, usually several full turns. Turn a lever a quarter turn so it sits across the pipe instead of along it.
- Confirm the water stopped.Open a faucet inside. Flow should slow to a trickle and stop as the lines drain. If water keeps coming, the valve is not seating and you need the curb valve.
- Drain the lines.Open a faucet at the lowest point of the house and a tub spout to relieve pressure, which reduces what leaks out of the break.
- Protect the water heater.If the main will be off for a while or the break is on the hot side, turn the heater's gas control to off or pilot, or switch off its breaker.
When the house valve will not stop the water
- IfThe wheel turns but water keeps flowingThenThe gate inside has likely failed. Close the curb valve at the meter if you have a meter key.
- IfThe valve will not turn at allThenStop forcing it and use the curb valve, or ask the city water utility for help at the meter.
- IfThe valve leaks from the stem after closingThenA small drip at the handle is common on old valves. Put a bucket under it and mention it to the plumber.
- IfYou cannot find any valve near the houseThenClose the curb valve, then have a plumber locate the house shutoff or install one where the line enters.
Shutoff readiness check
Ten minutes on a quiet weekend saves a lot of panic later.
- Find the house shutoff and clear plants or boxes around it
- Turn it closed and back open once to make sure it moves
- Tag it so anyone in the house can find it
- Locate the meter box and check whether you need a meter key
- Show everyone in the household where both valves are
- Know where the water heater's cold inlet valve is
Common questions
Is it safe to exercise an old shutoff valve myself?
Usually, if you use hand pressure only. If it is stiff or starts to leak at the stem, stop and ask a plumber to replace it with a ball valve, which turns more easily and seals more reliably.
Can I use the curb valve at the meter?
It is generally the backup shutoff, but it often needs a meter key and it may be considered part of the city's equipment. Check with the City of Fullerton water utility about using it.
Does closing the main turn off my irrigation too?
On many homes yes, but some irrigation systems branch off before the house valve. Check where your irrigation line connects.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.