Start at the meter
The EPA's WaterSense program puts the scale of it plainly: the average household's leaks waste more than 9,300 gallons a year, and nine percent of homes have leaks wasting 50 gallons or more a day. Its test: read the water meter, use no water for two hours, and read it again. If the number moved, water is leaving the system somewhere.
Then close the main shutoff valve at the house (not the meter) and repeat. If the meter still moves with the house valve closed, the leak is between the meter and the house — the service line or the irrigation system. If it stops, the leak is inside the house.
Inside the house: toilets first
The EPA notes that most toilet leaks are worn flappers, and a flapper leak is silent — water runs from the tank into the bowl and away without a sound. Put a few drops of food colouring in each tank, wait fifteen minutes without flushing, and look for colour in the bowl. A $100–$175 flapper or fill-valve repair ends a leak that can run thousands of gallons a month. The running-toilet guide covers the rest.
After toilets: the water heater's relief valve discharge pipe (a drip there is water down the drain you never see), the water softener (a stuck regeneration cycle runs continuously), a dripping outdoor hose bib, and the ice maker line behind the refrigerator.
Outside, and under the slab
Irrigation is the usual outside answer: a broken head or a stuck zone valve runs water into the ground on a schedule you never watch. Turn the controller off for a day and repeat the meter test. A service-line leak shows as a wet or lush strip between the meter and the house.
If the meter moves with irrigation off and every fixture quiet, and the house valve stops it, but no fixture is leaking, the pipe under the slab is the remaining suspect. Warm floor spots, the sound of running water with everything off, and a water heater that runs constantly are the signs; the slab-leak guide takes it from there. Rosco Plumbing uses acoustic and pressure testing to locate it before anything is opened.
When to stop and call a licensed plumber
- The meter moves with the house valve closed — the service line or irrigation main is leaking underground.
- The meter moves with everything off, the toilets pass the dye test, and you cannot find it — that is a locating job.
- You hear water running with every fixture off, or a floor is warm in one spot.
- The bill has doubled twice in a row; Manatee County bills monthly, so two cycles is two months of water into the ground.
Rosco Plumbing's service call for leak detection in Manatee County is $75–$150, applied toward the repair.
Call (941) 345-2464 or request a free estimate. Residential service in Manatee County; ranges are planning figures, not quotes.
Have Rosco Plumbing contact you about this
Describe what you are seeing and Ross will call or text back with what it sounds like and what the visit costs — no obligation.
What changes in Manatee County
Three Manatee County specifics. Nearly every home here is slab-on-grade, so a supply leak that would drip into a basement elsewhere goes straight into the ground unseen. Irrigation is almost universal and runs year-round, so it is the first thing to rule out. And seasonal homes accumulate a whole summer of a silent flapper leak before anyone sees a bill; the county's water and sewer charges both rise with it, since sewer is billed on water used. The 1978–1995 homes with polybutylene supply lines — the polybutylene guide — are the ones where a slab leak is most likely.