What to Do When a Water Heater Fails
A failed tank releases 40 to 80 gallons at once, then keeps refilling and releasing until the supply is closed. Most heaters sit in a garage, a closet, or an upstairs utility room, so the water finds finished space quickly. Close the water and kill the heat source before anything else.
Do this now
Close the cold water supply valve on top of the tank. If it will not turn or you cannot reach it, close the main.
Kill the heat source. On a gas heater, turn the gas control knob to OFF. On an electric heater, shut its breaker off.
A tank that keeps heating with no water in it damages the element and creates a burn hazard while you are working around it.
Stay out of the water until it has cooled. Tank water is commonly held between 120 and 140 degrees.
It cools as it spreads, but the first wave off a failed tank will scald.
Photograph the tank, the connections, the drain pan, and the data plate with the serial number and build date.
Age of the tank and whether the pan was ever plumbed to a drain often decide the coverage question. Once the plumber hauls it away, that evidence is gone.
Follow the water. Check the room on the other side of the wall, the room below, and anything downhill from the heater.
What makes it worse
These are the ones that turn a manageable loss into an expensive one, or cost people their claim.
Don't relight the pilot or reset the breaker to see whether it still works.
Firing a tank that has lost water damages it further and is a real burn risk. It also muddies the claim if the second failure looks like the first one.
Don't let the plumber scrap the old tank before it is photographed and the failure is documented.
The tank is the evidence. Carriers ask what failed and how old it was, and a photo of the data plate answers both in one frame.
Don't assume the drain pan did its job.
Most pans are sized for a slow drip, not a tank that split open, and a large share of them drain to a line that was never connected to anything.
Don't dry only the room the heater is in.
Water runs under the bottom plate of the shared wall and wicks up the drywall on the far side. The wet material is usually in the next room, and nobody looks there.
Don't treat water that has been sitting for days as clean.
Category 1 water degrades as it sits. Once it has been in carpet pad at room temperature for a few days it is no longer clean water, and the pad comes out rather than getting dried in place.
The clock
Water heaters fail in rooms nobody sits in, so the discovery is usually late. Mold begins colonizing wet organic material in roughly 24 to 48 hours. A tank that has been weeping behind a wall for weeks is already a remediation job rather than a drying job, and the scope is set by how long it ran, not by how much water is on the floor now.
Call us when
- Water got past the pan and reached drywall, carpet, cabinets, or the subfloor.
- The heater is upstairs, or it shares a wall with finished living space.
- The tank has been weeping slowly and you are only now finding soft drywall behind it.
- The garage slab looks dry but the drywall along the bottom of the shared wall is stained or soft.
If it’s past what you can handle, call.
A person answers 24 hours a day. Even if it’s just a question.