Leak Detection

Signs of a Hidden Water Leak

• Your water bill spikes, but you're using water the same way
• You hear running or dripping water when nothing is on
• A spot on a wall, floor or ceiling feels damp, soft or warm
• A musty or mildew smell shows up in a room that should be dry
• Water pressure drops at several fixtures at once
• New cracks appear in the floor or foundation

Try the Water Meter Test First

You can check for a leak yourself in about an hour. Turn off every faucet, appliance and sprinkler. Then find your water meter and write down the reading. Many meters also have a small leak indicator, often a triangle or a tiny dial, that spins when water is moving.

Don't use any water for an hour, then check again. If the reading changed, water is going somewhere it shouldn't.

Before you call, rule out the easy one. A toilet that runs or leaks between flushes can waste a lot of water, and toilet repair is usually a quick fix.

How Non-Invasive Leak Detection Works

Acoustic detection. Sensitive listening equipment picks up the sound of water escaping from a pipe, even behind a wall or under concrete.

Electronic tracing. Tracing equipment follows the path of the water line, so the plumber knows exactly where the pipe runs before narrowing in.

Thermal imaging. An infrared camera shows temperature differences caused by water behind walls or under floors. Hot water leaks stand out clearly.

Using all three together is what makes the search non-invasive. Nothing is opened until the leak's location is confirmed.

Where Hidden Leaks Usually Turn Up

• Water lines under the concrete slab
• Pipes inside walls behind showers and tubs
• Ceilings below an upstairs bathroom
• The line between the water meter and the house
• Connections at the water heater and appliances

If the leak turns out to be under your foundation, our slab leak repair page explains your repair options.

And if what you smell is gas, not water, that's a different emergency. Leave the house and see our gas leak service.

What It Costs

• Standard leak search: $150 to $400
• Slab leak search with extra equipment: $300 to $600
• The repair itself: priced separately, once the leak is found

After the Leak Is Found

The plumber explains what failed and how to fix it. A single leaking fitting or joint is usually a simple repair. If the pipe is corroded in several places, patching may not last, and pipe replacement is often the better long-term fix.