Hunting down the leak you can't see.

Do the meter test before you call anybody. Turn off everything in the house that uses water, then find your water meter and watch the small leak indicator on its face. If that little triangle or wheel is turning with nothing running, water is going somewhere. Our hidden leak guide walks through it, including how to tell whether the leak is inside the house or out in the yard.

Where hidden leaks turn up

Start with the toilets. A flapper that doesn’t seal lets water trickle into the bowl all day, and you’ll never hear it. Put a few drops of food coloring in the tank and wait 15 minutes without flushing. Color in the bowl means a leak.

Past that, here’s where we look:

• The service line between the meter and the house. Watch for a soggy strip in the yard when it hasn’t rained, a patch of grass that grows greener than the rest, or water pressure that’s dropped off.
• Under the slab. In a slab-on-grade house, a pipe under the concrete can leak for a long time. A warm spot on the floor, the sound of running water with everything off, or carpet that’s damp along one line are the signs. More on slab leak signs.
• Inside walls and ceilings. Bubbling paint, a stain that keeps growing, drywall that’s soft when you press it, or a musty smell in one room.
• Irrigation lines and outside spigots, where water goes straight into the dirt.

One trick for a ceiling stain under a bathroom: notice when it gets worse. If it only shows up after someone showers, it’s likely the drain or the shower pan. The supply pipes feeding the shower valve have pressure on them all day, so a leak there stays wet whether anyone’s used that bathroom or not.

Whose leak is it?

In Huntsville, the utility’s responsibility ends at the water meter. A leak at the meter or on the street side is a call to Huntsville Utilities. Everything from the meter to your house belongs to you, and so does fixing it. Other cities around here usually split it the same way, but check with your utility.

Huntsville Utilities also has a leak adjustment policy that can adjust a bill for a hidden, underground, or concealed leak. Leaks you could see or hear, like a running toilet, don’t count. Call them and ask what they need from you, ideally before the repair, so you’re not hunting for paperwork afterward.

How we narrow it down

When you call, tell us what the meter test showed. That one answer points us in the right direction before we even get there.

Finding a hidden leak is mostly a process of elimination. We separate the house from the yard and the hot side from the cold, then keep splitting it up until the leak has nowhere left to be. The goal is to open a wall or a floor once, in the right spot.

Fixing it

There are three ways to go, and the right one depends on where the leak is and what shape the rest of the pipe is in.

A spot repair opens the wall, the floor, or the yard at the leak and replaces the bad section. That’s the right call for one leak in pipe that’s otherwise sound. Under a slab, it means breaking through the concrete, so the flooring over that spot has to come up.

A reroute leaves the leaking line where it is and runs a new one through the walls or the attic instead. It skips the jackhammer, and for a hot line under a slab it often makes more sense than digging.

When the pipe is failing in more than one place, it’s time to talk about a repipe. If this is your second slab leak in a couple of years, we’d lean toward rerouting or repiping over waiting for the third.

How urgent is it?

Water coming through a ceiling, or a meter spinning fast, means shut the main off now. Stay out from under a ceiling that’s sagging, and turn off the breaker for any light fixture near the wet spot.

A slow leak can usually wait a day or two. Don’t let it go for months. Water in a wall or under a floor keeps working on whatever’s around it the whole time.