Shut it down in this order
If you smell gas at any point, leave the house and call the gas utility or 911 from outside.
Stop the cold supply
Close the valve on the cold-water pipe entering the top of the tank. If it won't turn or the leak continues, close the main water shutoff for the house.
Turn off the heat source
For a gas unit, turn the control knob to off or pilot. For an electric unit, switch off its breaker. A tank heating with no water coming in can be damaged.
Relieve pressure
Open a hot-water faucet upstairs. This lets air in and reduces pressure in the tank so the leak slows.
Drain only if it is safe
If the tank must be emptied, attach a hose to the drain valve and run it to a floor drain or outside. Water from a recently heated tank can scald, so let it cool first.
Photograph the tank
Capture the data plate with the model, serial number and manufacture date, plus where the water is coming from. Insurers and plumbers both ask.
Slow drip versus sudden failure
A tank that weeps from a fitting, the temperature and pressure relief valve, or the drain valve can often be repaired. A tank that leaks from the bottom seam or from rust through the steel shell has failed and needs replacement. The second kind can release a large volume quickly, and because the tank refills from the supply line, the flow continues until someone closes a valve.
Slow leaks cause a different kind of damage. A drain pan, if one exists, may overflow without anyone noticing, and water travels under the bottom plate of the mechanical room walls into neighboring carpet. By the time a stain appears, the framing may have been wet for weeks, which also matters for insurance: a long-running leak is often treated differently from a sudden one.
Basement mechanical room versus garage
| Basement mechanical room | Garage |
|---|---|
| Water spreads into adjoining finished rooms under walls and carpet | Water runs toward the garage door, and may reach drywall on shared walls |
| Floor drains help only if the floor slopes toward them | Stored boxes, tools and items on the floor take the damage |
| Furnace, softener and electrical equipment may sit in the same water | Winter temperatures can slow drying and freeze standing water |
| Drying usually needs dehumidification because basements stay cool | Interior damage is limited unless the slab slopes toward the house |
Before the new heater goes in
- Ask the plumber whether a permit is required. Inside Town of Parker limits, ask the town's building division; in unincorporated areas, ask Douglas County.
- Add a drain pan with a line to a drain where the location allows it.
- Consider an automatic shutoff valve or water alarm next to the tank.
- Keep the failed tank's data plate photo and receipt with your claim records.
- Have wet drywall and framing around the old tank checked with a moisture meter before it is covered back up.
General information for Parker, not a quote or professional advice. In an emergency, call 911.