Shut off the water supply valve above the heater, then kill the power — gas valve to OFF on a gas unit, breaker off on an electric one. Then call. A failed tank holds 40 to 50 gallons that will end up on your floor, so the shutoff comes before anything else.
Step by Step
- Shut off the cold water supply. There is a valve on the cold inlet line at the top of the heater. Turn it clockwise until it stops. If it will not close or there is no valve, use the main shutoff for the house.
- Turn off the energy source. Gas: turn the gas control valve to OFF. Electric: switch off the breaker. Never leave an electric element energized in a draining tank — it will burn out.
- Keep clear of the water if it is anywhere near electrical connections.
- Contain and remove standing water to limit damage to flooring, drywall, and anything stored nearby.
- Note where the water is coming from — top, bottom, the T&P valve, or the tank body. That tells us immediately whether this is repairable.
- Call for service.
Do Not Drain It Yet
It is tempting, but a technician needs to see the failure to diagnose it, and draining a tank of scalding water without a plan for where it goes creates its own problems. Shutting off the supply stops the damage clock, which is what matters.
What the Source Tells You
A leak at the inlet or outlet connections, the drain valve, or the T&P valve is generally repairable. Water coming from the tank body itself is not — a corroded tank means replacement. If the T&P valve is discharging, that valve may have failed, or the system may genuinely be over-pressurized or overheating, which needs diagnosis rather than just a new valve.
If You Smell Gas
Leave the house first. Do not flip switches. Call the gas utility from outside, then call us. Gas around a water heater is an emergency, not a plumbing problem.
Preventing the Next One
Annual flushing, anode rod replacement, a working pressure reducing valve, and a water softener for Albuquerque’s hard water.
We answer emergency plumbing calls 24/7. Contact B. Carlson.
