Why this comes first
Every other guide on this site starts with stopping the water. In a leak, the difference between a towel and a ruined floor is often how quickly someone can close the right valve. Newer homes tend to have a main shutoff, individual fixture stops and sometimes a PEX manifold with a valve for each line, which means you can often isolate a problem without cutting water to the whole house.
Builders place valves differently, so the only way to know your layout is to walk it. Do it on a calm day, with someone else in the household, and label what you find.
Where to look
| Shutoff | Common locations | What it controls |
|---|---|---|
| Main house shutoff | Near the front hose bib, on the garage wall, or in a box by the foundation | All water into the house |
| City meter valve | In the meter box near the street | Utility side; use a meter key and only in an emergency |
| PEX manifold | Garage, utility closet, or near the water heater | Individual hot and cold lines to fixtures |
| Water heater valves | On the cold inlet, and on tankless units both hot and cold service valves | Water to and from the heater |
| Fixture stops | Under each sink, behind each toilet, behind the washer and fridge | One fixture or appliance |
A shutoff walk-through
Find the main
Trace the water line from where it enters the house. Look for a lever or wheel handle.
Test it gently
Close it slowly and open a faucet to confirm the water stops. Open it again slowly.
Map the manifold
If you have one, check whether each valve is labeled. Add labels for kitchen, baths and laundry.
Check fixture stops
Turn each one a little to see that it moves. Do not force a stuck valve.
Note the heater valves
Find the cold inlet valve and, on a tankless unit, the service valves.
Write it down
Keep a simple map on the fridge or inside the garage door.
Keep these near the main
Ask during your next plumbing visit
- Are any of my shutoffs worn or stiff enough to replace?
- Would adding a valve at the manifold or heater make repairs easier?
- Is my main shutoff the type that closes fully?
- Should I consider an automatic leak-detection shutoff?
Common questions
Can I use the valve at the city meter?
It is on the utility side. In a true emergency you may need it, but it often needs a meter key and the city may prefer you call them. Check with the City of Fullerton water utility.
My house has no manifold. Is that wrong?
No. Many homes run branches with tees instead. You will rely more on the main and fixture stops.
Should fixture stops be replaced over time?
Older multi-turn stops can seize. Many plumbers suggest replacing worn stops when doing other work at that fixture.
General information for Amerige Heights, not a quote or professional advice. In an emergency, call 911.