A spot on the floor that’s warm to bare feet, or a water heater that runs all the time even when nobody’s using hot water? That’s often a leak in the hot line under the slab. Call or send a few details, and a local slab leak plumber will get back to you.
The signs
A hot water slab leak tends to give itself away. You might notice:
- a warm patch of tile or concrete, often in a hallway, kitchen, or bathroom
- the water heater firing up over and over, or running out of hot water sooner
- a gas or electric bill that went up along with the water bill
- the sound of water running somewhere under the floor
A quick check you can do
Turn off every faucet and water appliance in the house. Look at the water meter. If it’s moving, close the cold water valve at the top of the water heater and look again. If the meter stops, the leak is likely on the hot side. If it keeps moving, it’s probably somewhere on the cold side or before the heater. Either way, call a slab leak plumber to confirm and pinpoint it.
If you can’t get water to stop leaking and the floor is getting wet, shut off the main valve. On a gas heater, set it to pilot or vacation. On an electric one, turn off its breaker.
Why hot lines go first
Hot water lines expand and contract every time hot water runs through them, and that movement rubs the pipe against concrete and gravel where it passes under the slab. Heat speeds up corrosion too. Those are the main reasons hot lines tend to leak before cold ones.
Fixing it
The fix is the same set of choices as any slab leak. The plumber can open the floor at the leak, reroute the hot line through the attic or walls, or, if the house has had more than one leak, quote a full repipe. Rerouting hot lines is common because once one hot line leaks, the rest of it is the same age. See pipe rerouting.
Warm floor? Don’t wait on it. Call or send the details.