Leaking water heater: when to repair, when to replace
One question settles it: is the water coming from a connection, or from the tank itself? Connections are fixable. Tanks aren't.
Find the leak first
| Leak source | Verdict | 2026 cost |
|---|---|---|
| Inlet/outlet fittings on top | Repair | $100 – $300 |
| Temperature & pressure relief valve | Repair (often signals pressure issues) | $150 – $400 |
| Drain valve at bottom | Repair | $100 – $250 |
| Heating element gasket (electric) | Repair | $150 – $350 |
| Tank body / seam / bottom | Replace — no repair exists | $600 – $3,100 |
A tank-body leak means the glass lining has failed and the steel is rusting through. No sealant, weld, or part fixes it. That's also why a slow drip from the bottom of the jacket is more serious than a spraying fitting on top.
The age rule
Under 8 years old with a component leak: repair, and check the anode rod while the plumber's there — a $50 part that can add years. Over 10 years old: replace even for repairable leaks. Repairs on a 10+ year tank are down payments on the next failure, and the T&P valve leak that "keeps coming back" on an old tank is often sediment and over-pressure — the tank telling you it's done.
If it's actively flooding
Close the cold inlet valve on top of the heater; if that valve is seized, shut the house main. Kill the fuel: gas valve to off, or the breaker for electric. Then drain the tank through a garden hose to the nearest floor drain. Ten minutes of action turns a flood into a puddle.
Check the warranty before paying anything
Tank warranties run 6–12 years on the tank itself. A leaking in-warranty tank gets you a free replacement unit — you pay labor only, which turns a $2,000 problem into a $500 one. Find the manufacture date on the rating plate serial number before authorizing work.
Questions people ask
Can a leaking water heater tank be repaired?
No. Leaks from fittings, valves, or element gaskets are repairable for $100–$400, but a leak from the tank body means the lining has failed — replacement is the only fix.
Is a leaking water heater an emergency?
A tank-body leak is — it only gets worse and can dump 40+ gallons plus the live feed. Shut the cold inlet and fuel supply immediately, then get same-day replacement quotes.
How do I tell where my water heater is leaking from?
Dry everything with a towel, then run paper towel around the top fittings, the relief valve outlet, the drain valve, and the seam at the jacket bottom. Water at the bottom seam with dry fittings above means the tank itself has failed.