Showers rarely have their own shutoff you can reach
Toilets and sinks usually have a small valve under them. Showers and tubs are different: their only isolation is a pair of stops built into the valve behind the trim, and many older valves don't have those at all. That means the house main is often the only fast way to stop a shower leak.
In a typical Fullerton tract home, the main shutoff is near where the supply line enters the house, often on an outside wall facing the street, and the city's meter sits in a box near the curb. Find yours now, while nothing is leaking.
Your shutoff map
| Shutoff | Where it is | Type (lever, wheel, screw) | Last tested |
|---|---|---|---|
| House main | |||
| Shower valve stops | Behind trim? Yes / No | ||
| Toilet supply | |||
| Sink hot and cold | |||
| Water heater cold inlet | |||
| Meter (city side) | Curb box | Usually needs a meter key |
Testing the main shutoff
- Open a faucet.Turn on a tub spout or outside faucet so you can see when the water stops.
- Close the main.Turn a wheel valve clockwise or a lever a quarter turn. Don't force a valve that won't move.
- Confirm it stops.Flow should drop to nothing within a minute. A trickle means the valve isn't sealing fully.
- Reopen slowly.Open the main gradually to avoid a pressure surge, then close the faucet.
Keep near the main
- A tag or label on the main shutoff
- A note of this map's location inside the house
- A flashlight
- The non-emergency number for the city water utility, written down
- A towel and bucket in the bathroom closet
Ask a plumber on the next visit
- Does my shower valve have stops, and can you show me how to use them?
- Is my main shutoff in good condition, or does it need replacing?
- Would adding valve stops or a better main shutoff make sense?
Common questions
What if my main valve is stuck?
Don't force it, since an old valve can break. Have a plumber look at it, and contact the city water utility if you need water off urgently.
Do I need to turn off the water heater too?
Not for a shower leak in most cases. If the house will be without water for a long time, ask a plumber about the heater.
Where are shower valve stops?
When present, they are small screw or slot valves on either side of the valve body, visible once the trim plate is removed.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.