Hot Water Heater Burst: What to Do First, and Who to Call

When a hot water heater or hot water tank bursts, shut off its energy source (the breaker for an electric heater, the gas control and gas valve for a gas one), then close the cold-water inlet valve on the pipe entering the top of the tank. The tank is connected to a supply that keeps refilling it, so until that valve is closed, the leak has no end. After that, the order is: drain what is left once it has cooled, photograph everything, get the wet floors and walls dried, and have a plumber replace the heater.

Is It Safe to Go Near a Burst Water Heater?

Usually, with three cautions.

• Scald risk. The water in a heater is hot enough to burn, and a split tank or a failed fitting can spray it. Do not reach across an active spray. Stay out of standing water that is still steaming, and wear shoes, not bare feet.
• Electricity and water. An electric heater runs on a high-voltage circuit. If you would have to stand in water to reach it, do not touch the unit; go to the breaker panel from a dry spot instead.
• Gas. If you smell gas, do not touch switches or the heater. Leave the house and call your gas utility from outside.

1. Shut Off the Power or Gas

Electric heater: switch off its breaker at the panel. It is usually a double breaker labeled "water heater" or "WH". This also protects the heating elements, which burn out quickly if they run without water around them.

Gas heater: turn the gas control knob on the front of the unit to OFF. Then close the gas shutoff valve on the supply line beside the heater: a quarter turn, so the handle sits across the pipe instead of along it. If the burner area was flooded, do not relight the pilot yourself later; the control valve needs to be checked by a plumber or the gas company first.

2. Close the Cold-Water Inlet Valve

The cold inlet is the pipe entering the top of the tank, usually on the right, often marked with blue. Its valve is a lever (quarter turn) or a round handle (turn clockwise until it stops). The hot outlet pipe will be warm to the touch; the cold one will not.

If the valve is seized, missing or unsafe to reach, close the house main instead; the emergency water shutoff guide shows where it usually is.

3. Drain the Tank Safely

If the tank split wide open, it will empty itself onto the floor, and there is nothing left to drain. If it is leaking from a fitting or a smaller crack, draining the rest yourself keeps it off the floor:

1. 1Give it time to cool if you can. A full tank of hot water through a hose is a burn hazard at the far end too.
2. 2Attach a garden hose to the drain valve near the bottom and run it to a floor drain, a sump or outside, below the level of the valve.
3. 3Open a hot-water faucet somewhere in the house, or lift the lever on the temperature-and-pressure relief valve, to let air in so it drains.
4. 4Open the drain valve. Plastic drain valves on older tanks can break; turn it gently.

While it drains, move boxes and anything upholstered out of the water.

4. Photograph the Damage and Get It Dried

Before cleanup goes further, photograph the heater and its data label, the failed spot, the water on the floor, the bottom of nearby walls and anything stored nearby. The documentation guide lists what an adjuster looks for.

Then deal with where the water went, which is the part that costs money.

Hot Water Heater Burst Damage: Where the Water Goes

A burst tank dumps its full contents at once, 40 to 80 gallons on a typical residential tank, plus whatever the supply added before you closed the valve. That water does not stay in the closet.

• Into the walls. Heaters sit against drywall. Water wicks up the bottom of the wall and behind the baseboard, where you cannot see it.
• Under the floor. On a wood-framed floor it soaks the subfloor and runs along joists. On a slab it moves along seams and under flooring into the next room.
• Down a level. A heater in a closet on an upper floor or in an attic puts water into the ceiling below. Check that ceiling before anything else.
• Into mold conditions. The water is warm, and heater closets are closed. The EPA advises drying wet materials within 24 to 48 hours to prevent mold; how fast mold grows after water damage explains why warm, enclosed spaces are the worst case.

A restoration company finds the wet with a moisture meter and usually a thermal camera, removes what cannot be dried (carpet pad, sometimes the bottom of the drywall), and dries the rest, taking readings until the materials are back to normal. Most residential water damage jobs cost around $2,000–$6,000; a failure that ran for hours, reached a finished basement or came through a ceiling can go well beyond that. The heater itself is a separate plumbing bill, covered on the water heater replacement cost page.

Who to Call When a Water Heater Bursts

Two trades, two jobs. The plumber replaces the heater; the restoration company dries everything the water reached. The who to call for a leaking water heater guide covers reading a smaller leak in more detail. For a burst tank, this is the order:

If water got past the heater closet, (888) 840-6512 connects you to a certified water damage restoration company covering your ZIP, so the drying starts while you wait on the plumber.

Does Homeowners Insurance Cover a Burst Water Heater?

The pattern across most homeowners policies: the water damage from a sudden tank failure is usually covered, and the heater itself usually is not, because a tank wearing out is maintenance. The word that decides these claims is "sudden". A tank that split overnight is sudden. Rust trails, mineral crust and a stained platform tell an adjuster a leak was long-running, and long-running leaks are commonly excluded. Keep your photographs and the plumber's note on what failed. The water heater insurance guide covers exclusions, equipment breakdown endorsements and how to file.

Water Heater Burst in an Apartment

If you rent, the heater and the building are your landlord's, and so is the decision about who dries it. Do what is safe and in reach: if the heater is inside your unit and you can reach the cold inlet valve safely, close it, and keep clear of hot water. Move your belongings out of the water and photograph them.

Then notify your landlord or property manager in writing, by email or text, with the time you found it and photos, even if you also call them. Written notice is what shows you reported it promptly. Your landlord arranges the plumber and any drying. Damage to your own belongings falls under your renters insurance, not the landlord's policy; see does renters insurance cover water damage.

What Happens When You Call

If you own the home and the water reached walls, floors or a ceiling, here is what calling (888) 840-6512 sounds like. You hear a short automated menu first: press 1 for water damage, then enter the 5-digit ZIP of the property. The line goes quiet for about half a minute while it connects you to a certified restoration company taking calls in that ZIP. That is normal; stay on. When someone answers, say the water heater burst and describe what is wet.

Have four things ready:

• The property address, including the ZIP
• When the heater burst or when you found it, as near as you know
• What is wet now: which rooms, floors, walls or ceilings, and whether the water is stopped
• Whether you have opened an insurance claim yet

The company gives you an arrival window for your address on that call. Scope and price are between you and them, and there is no charge for the referral.

The Short Version

Power or gas off, cold inlet closed, tank drained once cool, photos taken. The plumber replaces the heater; if water went past bare concrete, a restoration company dries the rest. The appliance leak emergency page has the same steps on one screen.