Immediate Action: Do This Now
- Close the cold water supply valve on the pipe entering the top of the heater.
- Gas heater: turn the gas control knob to “off” or “pilot.” Electric heater: switch off its breaker.
- If water is pooling near an attic heater, check the ceiling below and move belongings.
- Do not touch the temperature and pressure (T&P) relief valve or its pipe; the water may be scalding.
- Request help and say where the water is coming from: top fittings, T&P valve pipe, or the tank bottom.
What Causes a Leaking Water Heater?
Where the water comes from usually tells you what failed.
Tank corrosion
Water from the tank body or bottom usually means the inner tank has rusted through. Dallas’s moderately hard water speeds sediment buildup and wear.
Fittings and valves
Leaks from the inlet, outlet, or drain valve can usually be repaired.
T&P relief valve discharge
Can mean excessive pressure or temperature, or a worn valve.
Condensation
Some moisture on a new heater or in very humid weather can be normal.
How Serious Is a Leaking Water Heater?
Tank leaks get worse, not better, and a failing tank can release a lot of water at once. Many Dallas homes have water heaters in attics or closets, where a leak can damage ceilings and floors below. Treat it as urgent until the water is off.
What Should You Do Before the Plumber Arrives?
- Keep the supply and fuel off until the plumber arrives.
- Place a pan or towels under the leak if it is safe to reach.
- Note the age of the heater from the label or serial number.
- If you smell gas, leave and call Atmos Energy or 911 from outside.
Can It Be Repaired or Does It Need Replacement?
Fitting, valve, and drain valve leaks are repairable. A leak from the tank itself cannot be repaired, and the heater needs replacement. This is also a good moment to consider a tankless unit.
How Much Can Emergency Water Heater Leak Repair Cost?
Emergency and after-hours visits typically cost more than scheduled work, and the total depends on what failed and how hard it is to reach. We do not publish a price for this specific repair. See emergency plumber cost, water heater replacement cost for published ranges with linked sources, and ask before work starts whether there is a dispatch or after-hours fee and whether it is credited toward the repair.
Related Problems
FAQs
Can I still use hot water?
Not safely while it is leaking. Keep the supply and fuel off until it is assessed.
How old is too old?
Tank heaters commonly last about 8–12 years. A leaking tank in that range is usually a replacement candidate.
Shut off the water first if you can, then request emergency help.