Your Home's Shutoffs: Water, Gas and Electric
Why this matters
When a pipe lets go, the water keeps coming at full pressure until somebody closes a valve. A household that already knows where that valve is closes it in a minute or two. A household that has to hunt for it, in the dark, with water on the floor, can lose ten minutes or more, and every one of those minutes is water soaking into drywall, flooring and the ceiling below. The same is true, in a different way, for gas and electricity: knowing which control is yours to touch and which belongs to the utility keeps a bad moment from becoming a worse one.
This card is a map. Walk your house with it once, put a tag on each valve and switch, and you will never have to search for one again.
The map: what is where
Every house has the same set of controls. Where they sit changes with how the house is built, but the list does not.
STREET / UTILITY SIDE | HOUSE SIDE
|
[curb valve]--[water meter]---+--[MAIN WATER VALVE]
utility owns (box in yard | |
needs a key or basement) | +--[water heater cold
| | inlet valve]
| +--[fixture stops:
[gas meter] | sinks, toilets,
| meter valve on inlet pipe | washer, fridge]
| (utility / responders) |
+----------------------------+--[appliance gas valve
| at furnace, water
[electric meter] | heater, range, dryer]
| outdoor disconnect, if any|
+----------------------------+--[MAIN BREAKER, top of
| panel] -> branch
| breakers by circuit
The two items in capitals are the ones every adult in the house should be able to reach and operate without thinking. The items on the street side of the line are the utility's, and the card below says why you mostly leave them alone.
Where each one usually sits, by house type
Main water valve. It sits where the water service enters the house, usually on the wall that faces the street, because that is where the pipe comes in from the meter.
- Basement house: on the front foundation wall, low, often within a few feet of the water meter if the meter is indoors. Look for the pipe coming through the concrete and the first valve on it.
- Crawlspace house: sometimes just inside the crawlspace access, sometimes far back under the house near where the line enters. Some builders add a second valve in a utility closet or under the kitchen sink. If yours is only in the crawl, that is worth knowing before an emergency, not during one.
- Slab house: the line comes up through the slab, so look in the garage near the water heater, in a utility or laundry closet, or on an outside wall near a hose bib. In warm climates the main valve is often outdoors, in a box near the foundation or at the meter itself.
Fixture stops. Small valves, usually an oval or round handle, under each sink, behind each toilet near the floor, in the box behind the washing machine, and on the line feeding an icemaker or water filter. They let you shut off one fixture and leave the rest of the house running.
Water heater cold inlet. A valve on the cold pipe going into the top of the water heater. Closing it stops the tank from refilling. It does not stop the hot water already in the house from flowing, and it does not drain the tank.
Gas meter and appliance valves. The meter is outside on most houses, on a side or back wall. Inside, every gas appliance (furnace, water heater, range, dryer, fireplace) should have its own shutoff on the pipe feeding it, usually a small lever valve within a few feet of the appliance.
Electric panel and main breaker. The panel is a gray metal box, often in the garage, basement, utility room or a hallway closet. The main breaker is usually the large breaker at the top, labeled with a number like 100 or 200 (the rating in amps). Some houses, especially newer ones and some with the meter on an outdoor pedestal, have a separate disconnect outside at or near the meter.
How to tell open from closed
You do not need to turn a valve to know where it is set. Read the handle.
| Control | Open looks like | Closed looks like |
|---|---|---|
| Lever (ball) valve, water or gas | Handle lined up with the pipe | Handle across the pipe, at a right angle |
| Round wheel (gate or globe) valve | Turned fully counterclockwise | Turned fully clockwise, snug |
| Fixture stop, oval handle | Turned counterclockwise | Turned clockwise until it stops |
| Breaker | Handle toward the center of the panel (ON) | Handle toward the outside edge (OFF) |
A lever valve goes from fully open to fully closed in a quarter turn. A round wheel valve takes several full turns. That difference matters in an emergency: if your main is a wheel, expect it to take longer, and expect an old one to be stiff.
Which ones you operate, and which ones you leave alone
Yours to operate. The main water valve, the fixture stops, the water heater cold inlet, and the main breaker and branch breakers (handles only). These are designed to be worked by the person who lives in the house.
The utility's, not yours. The curb valve (sometimes called a curb stop), buried near the street or the property line, belongs to the water utility in most places. It usually needs a long key to reach, and many utilities ask that only their crews operate it, because a broken curb valve becomes their dig. If your indoor main fails, call the water utility's emergency number and ask them to close it. The meter seal and the electric meter itself are also the utility's; never pull an electric meter.
The gas meter valve: leave it to the gas utility or the fire department. There is a quarter-turn valve on the pipe coming into the gas meter. Most gas utilities ask homeowners not to operate it except when they or emergency responders tell you to, and some areas with earthquake risk give their own instructions about when to close it. The reasons are practical: closing it puts out every pilot light in the house, and turning it back on without relighting every appliance correctly can leave gas flowing to an unlit burner. If you close the gas at the meter for any reason, do not turn it back on yourself. The gas utility or a licensed gas technician restores service and relights each appliance.
If you smell gas, do not go looking for a valve. Leave the house with everyone, do not flip any switch, light, appliance or phone inside, and call 911 or the gas utility's emergency line from outside and away from the building. Finding the meter is not your job at that moment. See related: When to Stop and Call a Licensed Pro Around the House.
Appliance gas valves. These are the small lever valves at each appliance. A technician uses them to isolate one appliance for service. Closing one at the request of a technician on the phone is reasonable. Reopening one after a repair is the technician's job, because the appliance has to be relit and checked.
Tag them once, and the job is done
A tag turns "I think it is somewhere in the crawlspace" into a thirty-second walk.
- Hang a tag on each valve and on the panel door. A plastic tag on a zip tie or a wire works. Write what it controls: "MAIN WATER, whole house", "Water heater cold supply", "Kitchen sink, hot".
- Mark the direction. On a wheel valve, write "turn right to close." People freeze on that question with water spraying.
- Keep the tool where it is needed. If your main is a stiff wheel, or sits in a meter box with a lid that needs a screwdriver, keep the tool there or in a labeled spot nearby.
- Add the locations to your house records, including a phone photo of each one with something in the frame that shows where it is. See related: Your House Records File and What Goes In It.
Worked example: a crawlspace house, before and after
A couple in a crawlspace house had lived there two years without ever looking for the main water valve. A supply line under the bathroom sink let go on a weekday evening. Here is how it went, then how it would have gone with the map done in advance.
What happened. The leak spread across the bathroom floor while one of them looked in the garage, then the laundry room, then under the kitchen sink. Nothing there. The crawlspace access was a hatch in the hallway closet floor under storage boxes. Clearing the boxes, finding a flashlight and crawling about 20 feet to the front wall took most of the time. Total from first spray to closed valve: about 12 minutes.
What that cost in water. A broken sink supply line at normal household pressure can put out several gallons a minute. Take 5 gallons a minute as an illustrative figure for this line. Twelve minutes at 5 gallons a minute is 60 gallons, about the volume of a full bathtub and then some, spread across a floor and into the subfloor below.
The same night, with the map done. The bathroom had a fixture stop under that sink. Turning it clockwise would have stopped the leak at its source in under a minute, with the rest of the house still running. If the stop had been stuck, the next move was the main, tagged, with the closet kept clear and a flashlight hung at the hatch. Say that takes 2 minutes. Two minutes at the same 5 gallons a minute is 10 gallons, a towel job instead of a flooring claim.
The difference. Sixty gallons against ten, from the same leak, and the only change was knowing the order: fixture stop first, main second. The fixture stop is closest to the problem and leaves water on everywhere else; the main is the backstop when the fixture stop will not close or the leak is somewhere without one, like a pipe in a wall.
What would change this. If the leak had been near the electrical panel or near outlets, the first move would not have been the water at all. Water near electricity means staying out of the wet area and following the stop card first. And if the crawlspace had standing water or the hatch was the only way in at night, adding a second main valve in a reachable spot is a reasonable thing to ask a plumber about on the next visit.
Checking a valve before you need it
Knowing where a valve is helps only if it works. Old valves, especially round-wheel mains and fixture stops that have not moved in years, can seize, or start to weep at the stem when they finally move.
- Fixture stops: turn one clockwise until it stops, check that the faucet or toilet no longer fills, then turn it back open. If it will not turn by hand, do not use pliers on it. Note it and ask a plumber to replace it on the next visit.
- Main water valve: a lever main can be closed and reopened to confirm it works. On an old wheel valve, many plumbers suggest only checking that it turns slightly, because forcing a valve that has sat for decades can break the stem or start a leak at the packing. If it drips after you move it, close it back to where it was and call a plumber.
- Breakers: you do not need to test the main. Knowing which handle it is and that you can reach it is enough.
- Gas valves: do not test them. Knowing where they are is enough.
If any check turns up a seized or leaking valve, that is a normal, inexpensive repair for a plumber, and much better found on a Tuesday afternoon than at 2 a.m.
References
- Your local water utility's customer guidance on the curb valve, the meter and its emergency number
- Your gas utility's safety guidance on gas odors and meter valves, which sets the rule for your area
- See related: When to Stop and Call a Licensed Pro Around the House
- See related: Your House Records File and What Goes In It
- See related: Frozen Pipe Prevention + Thaw Reference