The toilet shutoff, often called an angle stop because the water turns a corner inside it, connects the water pipe coming out of the wall to the flexible supply line that feeds the tank. Turning the handle clockwise closes it. In an overflow, a leaking supply line or any tank repair, it is the valve you reach for first.
In homes that are several decades old, these valves may be original or close to it. Mineral scale from hard water and long periods without use can make the handle stiff, and the packing around the stem can start to drip once the valve is finally moved.
Using the valve in a hurry
Find it
Look low on the wall or floor behind the toilet, usually on the left side.
Turn clockwise
Turn the handle to the right until it stops. An oval handle may take several turns; a quarter-turn valve only needs a quarter turn.
Confirm it held
Flush once. If the tank does not refill, the valve has closed.
Fall back to the main
If the handle will not turn or water keeps flowing, shut off the water at the home's main and call a licensed plumber.
Shutoff valve problems
| Problem | What it means | Typical fix |
|---|---|---|
| Handle will not turn | Scale or corrosion has seized the valve | Replace the valve with the main shut off |
| Drips from the stem after turning | Worn packing around the stem | Sometimes a slight snug of the packing nut; otherwise replace the valve |
| Water still trickles when closed | Washer or seat inside is worn | Replace the valve |
| Green or white crust on the valve | Slow weeping and mineral deposits | Replace the valve and supply line |
| Supply line bulging or frayed | Line is at risk of bursting | Replace the supply line right away |
A once-a-year check
Testing the valve before you need it avoids surprises.
- Turn the handle clockwise until closed and confirm the tank stops refilling.
- Open it again fully and look for drips around the stem.
- Look at the supply line for kinks, rust, fraying or bulges.
- Check that the area around the valve is dry.
- Make sure everyone in the household knows where the main shutoff is.
What a valve replacement involves
- Water
- The main must be shut off, since the valve is upstream of everything in the bathroom
- Connection type
- Depends on the pipe: older homes may have copper or galvanized lines
- Usually paired with
- A new supply line, since the old one is already disconnected
- Good time to do it
- Any time the toilet is being repaired, reset or replaced
Questions to ask a plumber
- What type of pipe is the valve connected to, and how will the new one attach?
- Should the other shutoff valves in the house be checked too?
- Is the main shutoff in good working order?
- Will you provide the price in writing before shutting off the water?
Common questions
Why does my shutoff valve drip only after I use it?
Moving the stem disturbs packing that has hardened over the years. A slight snug of the packing nut sometimes stops it; otherwise the valve should be replaced.
Is a quarter-turn valve better?
Many people find quarter-turn valves quicker to close in an emergency. Ask a plumber what suits your pipes.
Where is the main shutoff?
In many tract homes it is near where the water line enters the house or at the meter. If you are unsure, ask a plumber to show you.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.