What to Do When a Pipe Bursts

By the Tempe Emergency Plumber team · Updated September 2026

Turn the Water Off First

Everything else can wait. Until the supply is closed, the pipe keeps delivering water at full pressure and the damage keeps growing, so this is the one thing worth doing before you even look at what is wet.

In most Arizona homes the main shutoff is a valve on the supply line where it enters the house at the front, usually near a hose bib and often inside a small access box or behind a shrub. A lot of homes also have a valve in the garage close to the water softener loop, which is easier to reach and does the same job. Turn it clockwise until it stops. If the house has neither, the meter box near the street has a shutoff, though it takes a meter key to operate and the lid can be heavy in summer heat.

If the valve will not move, do not force it. An old valve that snaps turns a leak into a flood. Leave it, call for help and use a fixture valve if the leak is under one sink or behind one toilet.

Deal With the Electrical Risk

Water on a floor near outlets, extension cords, power strips or appliances is the part of this that can actually hurt you. Do not walk through spreading water to reach a breaker panel, and do not stand in it while you reach for anything plugged in.

If the water is nowhere near anything electrical and the panel is dry and accessible, switching off the circuits for the affected area is worth doing. If it is not, stay out of the room and wait. A ceiling that is sagging or bulging with water is the other thing to leave completely alone: do not poke it to drain it, because the whole section can come down at once, and there are usually light fixtures and wiring in it.

Limit the Damage You Can Reach Safely

Once the water is off and the electrical risk is handled, move what you can lift. Rugs, boxes, electronics, papers and anything on a bottom shelf are the things that turn into a real loss. Getting furniture legs up onto blocks or foil keeps stain from wicking into a floor.

Photograph everything before you start cleaning up. Wide shots of the room, close shots of the wet area and a picture of the failed pipe if you can see it. Whether or not you end up making an insurance claim, having a clear record of what the water did and where it went costs nothing and takes two minutes.

Do not try to clamp, tape or epoxy a line that is still under pressure. It will not hold, and the attempt usually widens the opening.

Why Pipes Fail Around the Valley

Hard water is the slow cause. Water here carries a heavy mineral load, and decades of it moving through copper thins the pipe from the inside. Pinholes appear on the hot side first because heat speeds corrosion along, which is why so many first failures in older Tempe houses are on a hot line.

Polybutylene is the faster cause. Homes plumbed between the early 1980s and the middle 1990s often have gray plastic supply tubing with crimped fittings that grow brittle over time. When those fail, they fail at a joint and they fail suddenly, and one failure usually means others are coming on the same run. Our Ahwatukee plumbing page covers a part of the valley where housing of exactly that era is the norm.

Beyond those two, we see lines damaged by a nail or a screw during a remodel, exposed runs in unconditioned space that have baked through too many summers, and failures at the water heater connections in a hot garage.

What Happens When the Plumber Arrives

The first job is confirming the water is properly isolated, then finding the break rather than the wet spot. Water travels along framing and along the top of a slab, so the damp drywall is often several feet from the pipe that failed. Pressure testing and listening equipment narrow it down before anything gets cut, which is what keeps the opening small.

After that you get a choice, not an instruction. A single failure in otherwise sound copper is usually a spot repair. Repeat pinholes in the same run, or any failure in polybutylene, point toward replacing that run instead, because the next one is already on its way. You should see the failed section of pipe and hear both prices.

Arrange a Repair

If water is still spreading, call rather than read. If it is stopped and you are looking at the aftermath, it still needs the pipe repaired properly before the water goes back on. Tempe Emergency Plumber covers burst pipe repair at any hour, and if you cannot see where the water came from, leak detection comes first. A line under the concrete is covered on the slab leak repair page, and you can request a visit whenever you are ready.