Hot water pipe leak detection in Tucson, AZ

Signs of a hot water pipe leak

• The water heater runs far more than it used to. You hear the burner firing or the elements humming when no one has used hot water.
• Hot water runs out quickly, or is lukewarm at fixtures that used to be hot.
• The gas or electric bill has risen along with the water bill.
• A warm patch on the floor or a warm strip along a wall.
• A hissing sound near the water heater or a bathroom with everything off.
• Warm water from the cold tap for the first few seconds at one fixture.
• Humidity, fogged windows, or a musty smell in one part of the house.
• Lower pressure on the hot side than on the cold.

How to test for a hot water line leak yourself

You can answer this yourself in about 20 minutes.

1. Turn off every fixture and appliance that uses water.
2. Check the water meter. If it's moving, there's a leak somewhere.
3. Close the cold water inlet valve on top of the water heater. This shuts off supply to the whole hot side.
4. Wait a few minutes and check the meter again.

If the meter stops, the leak is on the hot side: the heater, the hot lines, or a recirculation loop. If the meter keeps moving, the leak is on the cold side or outside the house.

Tell us the result when you call. If it points to the cold side or the yard, see underground water line leak detection.

Why hot water pipes leak before cold ones

Hot pipes work harder. Each time hot water is used the pipe expands, and when it cools it shrinks.

Under a slab or where it passes through framing, that movement rubs the pipe against whatever it touches. Heat also speeds up corrosion inside copper, and it softens and ages plastic pipe and rubber seals faster than cold water does.

Recirculation systems add to this. A recirculating pump keeps hot water moving through a loop so the taps run hot immediately.

That constant flow wears the inside of copper pipe, especially at elbows and tees. Homes with a recirculation loop tend to develop hot side leaks earlier than homes without one.

Where hot water leaks are found

• Under the slab. The most common location in Tucson homes. See slab leak detection for the full process.
• In walls, at shower valves and at the stubs behind sinks and washing machines.
• In the attic, on lines that were rerouted overhead after an earlier slab leak.
• At the water heater. The inlet and outlet connections, the flex lines, the relief valve and its discharge pipe, and the tank itself.
• On the recirculation line, at the pump, the check valve, or anywhere along the return loop.

How we locate a hot water pipe leak

1. Confirm it's the hot side with the meter and the heater valve, as above.
2. Inspect the water heater. Fittings, flex lines, the relief valve discharge, and the pan are checked first, because a leak here's visible and simple.
3. Pressure test the hot system on its own to measure how fast it's losing pressure. If there's a recirculation loop, it's isolated and tested separately.
4. Trace the hot lines. Running hot water makes the pipe route show on a thermal camera through floors and walls. Metal lines are also traced with a locator.
5. Thermal scan. With the system pressurized and no fixtures running, a leak under a slab usually shows as a warm bloom that stays put. A pipe shows as a line. See thermal imaging leak detection.
6. Listen. A ground microphone on the floor or wall finds where the leak noise peaks.
7. Confirm and mark. Quiet leaks are confirmed with tracer gas. The spot is marked, and you're told which line it is.

Why hot water leaks are harder to feel in a Tucson summer

The classic sign of a hot water slab leak is a warm spot underfoot. In Tucson that sign is seasonal. In winter, a tile floor is cool and a warm patch stands out clearly.

From June through September, the slab is already warm, the afternoon sun heats floors near glass doors, and even the water coming from the cold tap is warm because the ground it travels through is hot. A leak that would be obvious in January can go unnoticed in July.

So in summer, watch the equipment instead of the floor. A water heater that fires when no hot water has been used, hot water that runs short, and a meter that stops when the heater valve is closed are the reliable signs in any season. If you notice your heater working harder in summer, when it should be working least, do the valve test.

Hard water plays a part too. Tucson's supply is mineral-heavy, and scale builds fastest where water is heated.

It collects in the tank, on relief valves so they no longer seat, and in recirculation check valves so they stick. Several of the "hot side leaks" we trace end at one of those parts and not at a pipe.

What affects the cost of hot water leak detection

• Where the lines run. Attic lines can be inspected directly. Slab lines have to be located from above.
• A recirculation loop. It adds a second line to isolate and trace.
• Floor covering. Tile shows heat and carries sound. Thick carpet and wood flooring hide both.
• Pipe material. Copper is easier to trace and hear than plastic.
• Season and house temperature. A cool, steady indoor temperature makes thermal work faster.
• More than one leak. Hot lines of the same age often fail in more than one place.

When a hot water leak is an emergency

Close the valve on top of the water heater. That stops a hot side leak and leaves cold water working in the house, which makes it the best first step in almost every case. Then call.

Treat it as an emergency if hot water is coming up through the floor, if there's steam or scalding water at the heater, or if the relief valve is discharging continuously. For a gas heater, turn the control to the pilot or vacation setting.

For an electric heater, switch off its breaker. An electric heater must not be left powered if the tank might run low, because the elements burn out when they aren't covered by water.

How to prepare for hot water leak detection

• Do the meter and heater valve test and note the result.
• If the leak isn't causing damage, open the heater valve again a few hours before the visit so the hot lines are pressurized and warm.
• Tell us whether you have a recirculation pump, and whether it runs on a timer.
• Clear access to the water heater.

Leak Detective locates the leak and doesn't repair it. Your plumber may repair the pipe at the mark, reroute the hot line overhead, or replace a heater component.

Afterward, repeat the valve test: with everything off, the meter should hold still. The heater should go back to cycling a few times a day, and your energy bill should fall along with the water bill.

Hot side leaks are among the most common problems we find when carrying out leak detection in Tucson, AZ, largely because so many homes here have copper hot lines under the slab.