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Water heater leaking from the bottom: what to do right now
Emergency guide
A bottom leak is usually the tank itself failing — a slow drip from the drain valve can be tightened or replaced, but water seeping from the tank seams means the unit is done. Shut off water and power/gas now; a failed tank can rupture.
What to do, in order
- Shut off the cold-water supply valve on top of the unit (clockwise). If it's stuck, shut the house main.
- Kill power: breaker off for electric units; gas valve to PILOT/OFF for gas units.
- If the leak is from the drain valve spigot: hand-tighten, or screw a brass hose-end cap with a washer onto it as a stopgap.
- If water is weeping from the tank seams or the base: the tank is compromised — start shopping replacements.
- Mop and contain: a 50-gallon dump is 400+ lbs of water heading for your floor drains (or not).
- Call a plumber with tank info: gas/electric, capacity, height — quotes come back faster.
Red flags — stop and call a pro
- Water pouring (not dripping) — shut the main and call an emergency plumber now
- Gas smell near a gas water heater — evacuate and call the gas utility, not a plumber
- Leaking plus scalding-hot output — a failed thermostat/TPR valve is a burn and rupture risk
- Any leak over a finished ceiling below
Prevention
Flush the tank yearly (sediment accelerates internal rust), check the anode rod every 3–5 years, and replace units at 10–12 years before they replace themselves.
This guide is maintained by the ee.ltd editorial team — reviewed for 2026. Browse all home repair guides or compare plumbing costs.
Related guides
- Sudden low water pressure in the whole house: diagnosis
- Clogged drain: when to plunge, snake, or call a pro
- Toilet keeps running: the 3 parts to check
- Find your main water shutoff before you need it at 2 AM
What this repair typically costs
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