Why map it now
A clogged kitchen sink is rarely an emergency on its own. It becomes one when a trap joint lets go under pressure, a dishwasher keeps pumping into a full basin, or a supply line under the sink starts spraying. In those moments people search cabinets with a flashlight while water spreads across the floor.
Spend twenty minutes with this worksheet and a flashlight. Find each control, test that it moves, and write down where it is. Then tape a copy inside the sink cabinet door.
Your shutoff map
| Control | Where it usually is | Where yours is |
|---|---|---|
| Hot water valve for the sink | Under the sink, left side, on the supply line | |
| Cold water valve for the sink | Under the sink, right side | |
| Dishwasher supply valve | Under the sink, often a separate small valve or a tee off the hot line | |
| Dishwasher power | A plug under the sink or a breaker in the panel | |
| Disposal switch and power | Wall switch near the sink, plug under the sink, breaker in the panel | |
| Refrigerator water line valve | Under the sink or behind the fridge | |
| Main water shutoff for the house | Often near where the water line enters the house, or at the meter box near the street |
How to fill it in
Empty the sink cabinet
You need to see the back wall and the floor of the cabinet.
Trace each line
Follow each flexible supply line from the faucet or dishwasher down to its valve.
Test gently
Turn each valve clockwise to close, then reopen. If it is stuck or drips at the stem, note it for a plumber instead of forcing it.
Find the main
Locate the house main shutoff and note whether it needs a tool. A meter box valve may need a meter key.
Label and post
Tag each valve with tape and post the finished map inside the cabinet door.
Note anything that needs attention
- A valve that will not turn or drips when moved
- Old rigid supply tubes or crimped lines
- Corrosion on the trap or trap arm
- No accessible main shutoff
- A water-stained cabinet floor
Common questions
Who controls the water meter in Fullerton?
The City of Fullerton runs its own water utility. Questions about the meter or the street-side valve should go to the city.
Should I exercise the shutoff valves regularly?
Many homeowners open and close them once or twice a year so they do not seize. If a valve is already stiff or leaking at the stem, have a plumber look rather than forcing it.
Does closing the sink valves stop a clogged sink from overflowing?
It stops the faucet from adding water. Also stop the dishwasher, since it has its own supply and drain.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.