How do I use my water meter to check for a leak?

The test only works if every water-using fixture and appliance is off. Even a small trickle will move the meter and make a clean reading impossible. Before you walk out to the meter, do a quick pass through the house.

1. 1Turn off all faucets, showers, and tubs.
2. 2Make sure no toilet is running or refilling.
3. 3Stop the dishwasher, clothes washer, and any ice maker.
4. 4Shut off irrigation, drip lines, and any evaporative cooler that draws water.
5. 5Check that a water softener is not mid-regeneration, since that cycle pulls water on its own.

Pick a window when the house can stay quiet for at least 10 to 15 minutes. If anyone flushes a toilet or grabs a glass of water mid-test, the reading is ruined and you start over.

This matters because the numbers add up fast. According to EPA WaterSense, the average household's leaks waste nearly 9,400 gallons of water per year, and household leaks nationwide total nearly 1 trillion gallons annually. EPA also notes that 10 percent of homes have leaks that waste 90 gallons or more a day. A meter test is how you find out if yours is one of them.

Your meter usually sits near the sidewalk or curb, in line with the main outside faucet on the front of the house. Look for a rectangular metal or plastic lid set into the ground, often marked "water" or "water meter." In Phoenix-area yards it is commonly in a concrete or plastic box near the property line.

Lift the lid carefully. Black widow spiders, scorpions, and other pests like these boxes in the desert, so use a screwdriver to flip the lid rather than bare fingers, and keep your hand clear until you can see inside. The lid can be heavy; pry it up at the slotted edge.

Once it is open, you will see one of two meter types: a digital meter with an electronic screen, or an analog meter with a round dial, number wheels, and a sweeping hand. Wipe off dust or condensation so you can read the face clearly. The reading method differs by type, so identify yours before moving on.

The reading method depends on whether your meter is digital or analog, but the principle is the same: with all water off, nothing should move.

On a digital meter, the screen may be asleep to save battery, so shine a flashlight on the face or pass your hand over the solar panel to wake it. The display often cycles between the total reading and a separate flow rate or flow-indicator screen. With all water off, watch the flow screen for at least 10 flashes or several full cycles. The City of Chandler's guidance is direct on what the result means: "any number above zero indicates that water is continuously running through the meter and you may have a leak." If the flow reading holds at zero through every flash, no water is moving and you likely have no continuous leak. Some digital meters also show a small leak icon, often a faucet or drip symbol, that turns on after steady low flow over many hours. If that indicator is lit, treat it as a strong sign of a slow leak.

On an analog meter, leaks show through movement. First, find the low-flow indicator: a small triangle, star, or gear on the dial face. This little marker is built to spin at the slightest flow, so it catches leaks too small to move the big sweep hand. Also note where the large sweep hand is pointing.

With all water off, write down the exact position of the sweep hand and watch the low-flow indicator. If the triangle, star, or gear is turning at all, water is moving right now and you have a leak. If it sits still, wait about 10 minutes without using any water, then look again. Any change in the sweep hand position, or any movement of the low-flow marker, means water left the system while nobody used it.

For a slow leak that is hard to catch by eye, use the two-reading method: write down the full meter reading, wait 1 to 2 hours with absolutely no water use, then read it again. If the number climbed, water escaped during that gap. This longer window catches the kind of slow weep a 10-minute look can miss.

A moving meter tells you water is escaping, but not yet where. The next step narrows it down to your side or the city's side. Find your main house shutoff valve, usually where the service line enters the home or in a wall box near the meter, and close it fully.

Now go back and read the meter again the same way you did before:

• If the meter stops moving once the main house valve is closed, the leak is somewhere inside the home or in the lines past that valve: a fixture, a slab leak, an irrigation line, or interior piping.
• If the meter keeps moving with the house valve shut, the leak is in the service line between the meter and the house, the buried pipe that feeds your home.

Where that buried-line leak falls can affect who pays for the repair. The split between the homeowner's responsibility and the city's depends on local code and where the break sits along the line, so check our page on who-is-responsible-for-sewer-line-phoenix for how that boundary works in the Phoenix area before you assume the cost is yours.

If the meter test points to an indoor leak, start with the toilet, because a silent toilet leak is the most common culprit and the cheapest to fix. EPA WaterSense reports that toilets account for nearly 30 percent of an average home's indoor water use, and a worn flapper can leak for weeks without a sound.

The dye test is simple. Drop a few drops of food coloring or a dye tablet into the tank, not the bowl, and do not flush. Wait about 10 minutes, then look in the bowl. If color shows up in the bowl water, the flapper is leaking and letting tank water slip past. A leaking flapper is usually a quick, inexpensive part swap; our how-to-fix-a-running-toilet page walks through the repair.

Run the dye test on every toilet, since more than one can leak at once. After fixing any leakers, repeat the meter test to confirm the movement has stopped. If the meter still creeps with all toilets sealed, the leak is elsewhere, often a slab leak, a dripping valve, or buried irrigation. Phoenix's hard water makes this worse over time; the USGS classifies water above 180 milligrams per liter of dissolved minerals as "very hard," and Phoenix water sits at the top of that range, which speeds up corrosion and scale that wear out flappers, valves, and fittings.

A confirmed meter reading with no visible wet spot points to a hidden leak: under the slab, inside a wall, or below the yard. Warm spots on the floor, the faint sound of running water with everything off, or a bill that climbed for no reason are all signs worth following up, and our high-water-bill-no-visible-leak page covers how to track these down. At that point the meter has done its job: it has told you, with certainty, that water is escaping. Pinpointing a buried or slab leak takes acoustic listening gear and thermal tools rather than a screwdriver and a flashlight. If your test shows steady movement you cannot trace, call a licensed plumber for leak detection before the water finds your foundation. Catching it early is far cheaper than repairing the damage that a slow leak leaves behind.