Leak detection and slab leak repair in Phoenix

The EPA’s WaterSense program gives two simple tests:

1. The meter test. Read your water meter, use no water at all for two hours, then read it again. If the reading has changed, you probably have a leak somewhere.
2. The toilet dye test. Put a few drops of food coloring in the toilet tank. If color shows up in the bowl within 10 minutes without flushing, the flapper or valve is leaking. Flush afterward so the dye does not stain the tank.

The EPA says the average household's leaks can waste more than 9,300 gallons of water a year, and that nine percent of homes have leaks wasting 50 gallons or more per day. The toilet test and a look at faucets and fixtures rule out the easy causes before you pay for detection.

One caution for Phoenix residents: Phoenix Water Services says the meter box and meter are city property, and tells residents not to try to turn off the water at the meter themselves. Reading the meter is fine; shut off your water at the house valve instead.

HomeAdvisor’s slab leak guide lists these signs:

• Warm or damp spots on the floor.
• Standing water or wet flooring with no visible source.
• A sudden change in water pressure.
• An unusually high water bill.
• The sound of running water when every fixture is off.

Our slab leak signs guide goes into each one in more depth.

These are national figures from HomeAdvisor, updated in June 2026. Repair cost depends heavily on where the leak is and how the contractor reaches it.

For leaks that are not under the slab, HomeGuide’s plumber cost guide lists leak repair at $150 to $850 and pipe repair at $400 to $2,000. Whole-house repiping runs $2,280 to $5,120 in the same guide.

A contractor usually starts by isolating the problem: checking the meter with the house valve closed, then testing hot and cold sides separately to narrow down which line is losing water. From there, the goal is to pinpoint the leak before anyone breaks concrete. Ask the contractor which method they plan to use, what the detection fee includes, and whether it is credited against the repair if you hire them.

Once the leak is found, the main choices are to open the slab and repair the pipe at that spot, or to reroute the line through walls or the attic and abandon the leaking section. HomeAdvisor's ranges for a reroute and for a spot pipe repair overlap, and a reroute avoids breaking the floor. If several leaks have appeared over time, ask whether repiping is the more durable answer.

Sometimes. Phoenix's work-exempt-from-permit list exempts stopping leaks in drain, water, soil, waste or vent pipe, and repairing leaking pipes, valves or fixtures when the repair does not require replacing or rearranging them. If a concealed pipe has to be removed and replaced, the city treats it as new work that needs a permit. A reroute or repipe changes the piping layout, so expect a permit for that. Ask the contractor who will pull it.

Policies differ, so read yours or ask your agent before work starts. Take photos and keep the detection report, the invoice and any permit paperwork, because an insurer will usually ask for them.

Search the business in the Arizona ROC contractor search and confirm the license is active. The ROC says Arizona requires a licensed contractor when the total project cost, labor and materials included, is over $1,000 or when the work needs a local permit, and it recommends checking that the license is current on the day you sign. Get estimates from at least three licensed contractors, avoid rushed decisions, and do not pay in cash or sign over an insurance check, as the ROC advises. Ask whether the contractor will be doing both detection and repair, and get the detection findings in writing, so you can get a second repair quote.

Our guide on how to choose a plumber in Phoenix lists more questions to ask.

Plumber Phoenix Pros is an independent guide and not a licensed contractor. We do not perform, price or schedule this work. To reach a plumber, call one of the licensed contractors listed on this page or see all listed contractors. If you prefer, you can email us your question through our contact page.