Hot water lines are the most common slab leak. They expand and contract every time hot water runs, and where the pipe rubs against gravel, rock or the edge of the concrete it slowly wears through. After twenty or thirty years of that, a pinhole opens under the floor.
The signs of a hot water slab leak
- A warm or hot spot on the floor. Often in a hallway, kitchen or bathroom, sometimes a warm strip following the pipe's path.
- A water heater that runs constantly or never quite catches up.
- A gas or electric bill creeping up alongside the water bill, because you're heating water that disappears into the ground.
- Less hot water than usual at taps and showers.
Walk the floors barefoot early in the morning, before the house warms up. A warm patch is easy to feel.
What to do first
You can often slow the loss by shutting the cold supply valve to the water heater until the repair, which stops it refilling the leak. Leave the heater's power or gas settings to the plumber if you're unsure.
How it's repaired
The hot line is isolated and the leak pinpointed through slab leak detection, usually with a thermal camera following the heat trail. Then there are two main options:
Section replacement. A small section of slab is opened at the leak, the worn pipe is cut out and replaced, and the line is pressure-tested before the concrete is patched. Sensible for a first leak on newer pipe.
Hot line reroute. The old hot line under the slab is abandoned and a new one runs through the attic and walls to each fixture. Common in older homes, where the rest of the hot line is the same age and likely worn. See slab leak repiping and reroute.
Why older homes here see more of these
Many homes around Cohutta and Varnell were plumbed with copper laid directly in the slab. In a single-storey ranch layout, the water heater often feeds the kitchen and bathrooms through one long hot run under the floor, and that run takes decades of heating and cooling.
Call for a quote on [slab leak repair](/) for a hot water line.
Hot Water Line Slab Leak Repair Services We Offer
✓Hot Spot Tracing
Thermal scan of the floor to follow the leak.
✓Section Replacement
Replaces the worn length of pipe through a small opening.
✓Hot Line Reroute
Runs a new hot line above the slab.
How it works
- 1
Heat trace
Thermal scan follows the hot water trail.
- 2
Isolate the hot line
Confirms the hot side is leaking.
- 3
Repair or reroute
Section replaced or line moved above the slab.
- 4
Pressure test
Line tested before patching.