# High water bill: how to find a hidden leak with the meter test

Updated: 2026-10-24 · https://pros411.com/en/guides/plumbers/hidden-water-leak-high-bill

## Short answer

Turn off every faucet and water appliance, inside and out. Find the water meter, usually in a box near the street, and look at the leak indicator, a small triangle or star. If it spins, water is leaking somewhere. Write down the reading, wait 30 minutes and check again. Then close the main valve at the house: if the meter stops, the leak is inside; if not, it is in the yard line.

## How to do the water meter test

![Cartoon water meter in its curb box looking at a sky-high water bill, with a cat watching](https://pros411.com/img/guias/hidden-water-leak-high-bill.webp)

1. **The bill jumped and you do not know why.** Before you call the utility, let the meter tell you. It counts every drop that goes into your house, leak or not.
2. **Turn off all the water, inside and out.** Faucets, showers, the washer, the dishwasher, the ice maker and the sprinklers. Make sure no toilet is refilling.
3. **Lift the lid: is the leak indicator spinning?.** The meter is usually in a box near the street. The small triangle or star turns with even a tiny flow. If it spins with everything off, you have a leak.
4. **Write down the reading and wait 30 minutes.** Take a photo of the numbers, wait without using any water and look again. If the numbers went up, water is going somewhere.
5. **Close the house valve to narrow it down.** Close the main shut-off at the house. If the meter stops, the leak is inside: check the toilets first. If it keeps moving, the leak is in the yard line.

## Where hidden leaks usually are

- A toilet with a worn flapper, the most common one: do the food coloring test.
- A dripping faucet or shower head.
- A sprinkler line or valve in the yard: look for a soggy spot.
- A water heater relief valve that drips into a drain.
- The line from the meter to the house, or a slab leak under the floor.

## How much a small leak wastes

More than you would think. The EPA estimates that leaks in the average home can waste more than 9,300 gallons a year. About 9 percent of homes have leaks that waste 50 gallons or more a day.

## What not to do

- Do not dig up the yard or open walls on a guess: narrow it down with the meter first.
- Do not lift the meter lid with your fingers: use a screwdriver and watch for spiders and wasps.
- Do not use the curb stop for the test: close the valve at the house.

## When to call a plumber

- The meter keeps moving with the house valve closed (a leak in the yard line).
- The meter stops with the house valve closed, but you cannot find the leak inside.
- You hear water running or feel a warm spot on the floor.
- You see a soggy patch in the yard or water bubbling near the meter box.

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## Frequently asked questions

### How do I know if I have a hidden water leak?

Turn off all water and watch the leak indicator on your meter. If it spins, or the reading goes up in 30 minutes with no water in use, you have a leak.

### Where is my water meter?

Usually in a concrete or plastic box in the ground near the street or the sidewalk, with a lid marked "Water". In cold areas it is often inside, in the basement.

### What is the leak indicator on a water meter?

A small triangle, star or wheel on the meter face that turns whenever water flows. It moves even with a slow leak that the big numbers barely show.

### What is the most common cause of a high water bill?

A running or leaking toilet. A worn flapper can leak silently all day; drop food coloring in the tank and see if it shows up in the bowl without flushing.

### Will the water company fix a leak on my side of the meter?

Usually not. The line from the meter to the house and everything inside is yours. Many utilities offer a one-time bill adjustment once the leak is fixed, so ask.

### Can a leak raise my bill without any water showing?

Yes. A leak under the slab, in the yard line or into a drain can run for months without a puddle. The meter test is how you catch it.

## Sources

- [EPA WaterSense: Fix a Leak Week](https://www.epa.gov/watersense/fix-leak-week)
