A leaking water heater requires immediate attention to prevent water damage, safety hazards, or complete system failure. The first critical step is to turn off the water supply and power (electricity or gas) to the unit to mitigate risks. Not all leaks mean the heater must be replaced—some can be repaired if they originate from fittings, valves, or supply lines, while leaks from the tank itself typically require full replacement due to corrosion or structural failure. Professional assessment is strongly recommended, especially for gas heaters or unclear leak sources, as improper handling can exacerbate the problem or create safety risks.

Key takeaways from the sources:

• Shut off utilities immediately: Turn off the water supply and power/gas to the heater to prevent further damage or hazards ^[1][3][5].
• Identify the leak source: Check fittings, valves, and supply lines first—these are often repairable, while tank leaks (especially at seams) usually mean replacement is needed ^[1][2][6].
• Condensation vs. leaks: New or heavily used heaters may produce condensation that mimics a leak; verify the source before taking action ^[1].
• Professional help is critical: For gas heaters, unclear leak origins, or major repairs, contact a plumber to avoid safety risks or voided warranties ^[3][5][8].

Addressing a Leaking Water Heater: Steps and Solutions

Immediate Actions to Take When a Leak Is Detected

The moment you notice water around your water heater, act quickly to minimize damage and safety risks. Start by turning off the water supply valve—typically located on the cold-water pipe entering the tank—to stop the flow of water into the unit. For electric heaters, switch off the circuit breaker labeled for the water heater; for gas models, turn the gas control knob to the "off" or "pilot" position ^[1][3]. These steps prevent electrical shocks, gas leaks, or further water release while you assess the situation.

Next, determine whether the water is from a leak or condensation. New water heaters or units working overtime (e.g., after a large hot water demand) may produce condensation on the tank exterior, which can pool underneath and mimic a leak. Wipe the tank dry and observe if water reappears—if it does, the issue is likely a true leak ^[1]. If the leak is confirmed, proceed with these critical steps:

• Drain the tank partially: Attach a garden hose to the drain valve at the base of the heater and direct it to a floor drain or outside. Open the valve to release pressure and reduce water levels, which can help slow the leak temporarily ^[4].
• Inspect accessible components: Check the following areas for visible leaks or moisture:
• Supply lines and fittings: Loose or corroded connections where pipes enter/exit the tank ^[3].
• Pressure relief valve (TPR): A leaking or dripping valve may indicate excessive pressure or a faulty valve ^[5].
• Drain valve: Ensure it’s fully closed; if leaking, it may need replacement ^[8].
• Tank seams or base: Leaks here often signal internal corrosion and require replacement ^[2][7].
• Avoid DIY repairs for gas heaters: Due to explosion or carbon monoxide risks, gas water heater leaks should only be handled by licensed professionals ^[1][3].
• Document the leak: Take photos for warranty claims or plumber consultations, especially if the unit is under 10 years old ^[4].

If the leak originates from the tank itself—particularly at seams or the base—replacement is the only solution, as tanks cannot be patched once corroded ^[2][7][9]. For repairable leaks (e.g., valves or fittings), proceed to the next section.

Determining Repair vs. Replacement

Not all water heater leaks require a full replacement, but distinguishing between repairable and non-repairable issues is crucial. The location and cause of the leak are the primary factors in this decision. According to professional plumbers and manufacturers, the following guidelines apply:

• Loose or damaged fittings: Supply line connections can be tightened or resealed with plumber’s putty or Teflon tape. If the threads are stripped, the fitting may need replacement ^[3][8].
• Faulty pressure relief valve (TPR): A leaking TPR valve often indicates excessive pressure (above 150 PSI) or a malfunctioning valve. Testing the valve by lifting the lever—if it doesn’t reseat or continues to drip, replace it ^[5][6].
• Drain valve leaks: If the valve is cracked or won’t close tightly, replacing it is a straightforward fix ^[8].
• Inlet/outlet valve issues: These can be replaced without replacing the entire unit ^[6].

• Tank seams or base leaks: Once the tank’s glass lining or metal corrodes, patches or sealants cannot reliably fix the issue. Attempting to weld or seal a corroded tank risks contamination or catastrophic failure ^[2][7][9].
• Internal corrosion: Signs include rust-colored water, metallic flecks in drained water, or visible rust on the tank exterior. This indicates the sacrificial anode rod has failed, and the tank is deteriorating ^[9].
• Age of the unit: Water heaters typically last 8–12 years. If the unit is older and leaking, replacement is more cost-effective than repeated repairs ^[4][6].

Additional considerations:

• Warranty coverage: Many manufacturers offer 6–12 year warranties on tanks. If your unit is under warranty, a professional inspection may cover replacement costs ^[4].
• Water damage risks: Even small leaks can lead to mold, structural damage, or electrical hazards. A plastic drain pan under the heater can mitigate this but isn’t a long-term solution ^[9].
• Professional assessment: If the leak source is unclear or involves gas lines, a licensed plumber should diagnose the issue. They can perform pressure tests, inspect the anode rod, or check for hidden corrosion ^[3][5][6].

For repairable leaks, temporary fixes (e.g., pipe clamps or epoxy for minor pipe leaks) may buy time, but permanent repairs should be prioritized ^[3]. If replacement is needed, consider upgrading to a more efficient model or adding a water alarm for early leak detection.