Article
If the meter moves while the house is quiet, water is leaving
A stain can be old. A drip under the sink can be the angle stop you already know about. The meter does not care about either story. With every fixture off, including the ice maker and the irrigation timer, a dial or a flow indicator that keeps moving means water is leaving the plumbing somewhere you have not found. In Los Angeles that is the start of a leak inspection, not the start of a demolition.
The Los Angeles Department of Water and Power tells customers to shut off all indoor and outdoor water and then look for movement on the meter. The EPA's WaterSense program adds a useful detail most local ads skip: compare the reading before and after about two hours of no use. A change means water passed the meter. Neither page tells you which pipe. That gap is where people get sold a slab leak from a single glance at a spinning indicator.
How to read the test without fooling yourself
Open the sidewalk box carefully. The lid is heavy, and it is the utility's box, so do not stand in the street to do it. Match the meter number to the bill if more than one box sits on the parkway. Apartment and back-house meters are easy to mix up. Note the reading, including the small digits, or the position of a low-flow indicator if your register has one. LADWP uses more than one register style, including straight-reading meters in cubic feet. Do not trust a blurry photo of a dial as a measurement. A photo is enough to book the inspection. It is not enough to price a repair.
Wait. A toilet that refills itself moves the meter in a short burst and then stops. A supply leak keeps moving, or it changes the reading across the two quiet hours. If you are not sure which you saw, leave the house valve as it is and tell us. Do not cycle the valve all evening to watch a stain. That only spreads water.
LADWP and the EPA both describe a simple toilet check that belongs in this test: a few drops of food coloring in the tank. If color shows up in the bowl without a flush, the flapper is leaking into the bowl and the meter is telling the truth about a toilet, not about a slab. Flush as soon as you see the color so it does not stain the china. A flapper is a small repair. It should not be described as detection.
The house valve splits the map in two
Close the house valve on your side of the meter, the one that feeds the building. If the meter stops, the loss is inside, on the house side of that valve. If the meter keeps moving, the loss is between the meter and the valve, which on many Los Angeles lots is the buried yard line. Those are different openings. We do not treat them as the same job. The practical steps for closing that valve, and for leaving it closed, are in how to shut off the water.
Inside the house, isolation is one branch at a time: irrigation, softener, water heater, toilet stops, and fixture stops. When the movement stops, that branch is the one. Then we listen. The loudest point on the plaster or the slab is where the mark goes. The mark is not permission to open the wall. The free version of this visit is described in what the free leak inspection includes.
What a moving meter is usually not
It is not a clogged kitchen. A drain can flood a floor without touching the meter. If the dial is still and a basin is full, stop looking for a slab and read kitchen sink full of water. It is also not proof that the pipe under the concrete has failed. The loss can be a hose bib, a softener stuck regenerating, a shower valve that weeps into the wall, or the toilet you just tested with dye.
Irrigation is the leak Los Angeles meters catch all night while the house stays dry. A drip zone that never quite closes will turn the indicator and leave the ceilings clean. Look at the controller and listen at the valves before you decide the slab is gone. A yard leak wastes the same water and it is often an easier repair. A softener that will not finish a cycle does the same thing from a closet.
If the dial will not sit still tonight, shut the house valve and call 818-631-7296. We cover Los Angeles, Van Nuys, Sherman Oaks, North Hollywood, Valley Village, Toluca Lake, Northridge, Glendale, Studio City, Calabasas, Beverly Hills, Woodland Hills, Pasadena, Santa Monica, Porter Ranch, and Santa Clarita. The inspection that sorts the meter from the drain is free. The repair after the mark is not. If the number is large enough that you want to talk about how to pay it, that happens after we know the job, on the financing conversation, not from a spinning dial alone.
Bills, indicators, and what we will not conclude
A high bill is a reason to run the test. It is not, by itself, a location. LADWP bills many residential meters in hundred-cubic-foot units and ignores the last two digits of a straight-reading register for the charge. A small leak can hide inside a billing period and still show on the low-flow indicator if you stand there. Compare two readings you took yourself, hours apart, with the house quiet. Do not compare this month's bill with last year's and call the difference a slab.
Point-of-entry alarms and whole-house monitors can tell you flow happened. They do not open the wall, and they do not know a drain from a supply line. If you have one, bring the alert time. We still confirm it at the sidewalk meter before anyone marks a floor. A monitor that cried at 3 a.m. is a clue about when. The shutoffs tell us where.
Questions people ask
Does a spinning meter mean I have a slab leak?
No. It means water is passing the meter while you think nothing is using water. The loss can be a toilet, a hose bib, a softener, an irrigation valve, a shower valve, or a line in a wall or under the slab. Isolation finds which.
How long should I watch the meter?
The U.S. EPA suggests comparing the reading across about two hours with no water in use. A short look can miss a toilet that refills in bursts. Write down every digit, not only the whole numbers.
What if the meter stops when I close the house valve?
The loss is on the house side of that valve. If the meter keeps moving with the house valve closed, the loss is between the meter and the valve, often the yard line. Those are different repairs.