Why is my water heater leaking?

Q: How much does it cost to fix water heater leaking?

$150–$2,500. Valve and fitting repairs are at the low end. Full replacement including labour, permit and disposal is the top of the range and higher for tankless conversions.

Q: Can I fix water heater leaking myself?

There are some safe steps to try first. Call promptly for any leak from the tank body, any leak you can't isolate, or a T&P valve that keeps discharging.

Short answer

Where it leaks tells you how serious it is. Leaks at the fittings, valves or the T&P discharge pipe are often repairable. Water coming from the bottom of the tank itself usually means the tank has corroded through — that isn't repairable, and the unit needs replacing before it fails completely.

Urgency: Urgent
DIY: Some steps you can try
Typical cost: $150–$2,500
Time: 1–2 hours for a repair

Urgent — days matter

Treat any tank leak as urgent. A corroded tank can go from a drip to a full rupture, releasing every gallon it holds. If water is flowing rather than dripping, shut off the water supply to the heater now.

What's happening

Water is escaping the system. A tank holds 40–80 gallons, so a failure can put all of it on your floor at once.

Most likely causes

01
Loose or corroded inlet/outlet fittings
Connections at the top can loosen over time. Often the easiest fix.
02
Failing drain valve
The valve at the base can drip after being used or as it ages.
03
T&P relief valve discharging
This valve releases when pressure or temperature is too high. It doing its job means something else is wrong — never plug it.
04
Corroded tank
Internal rust eventually perforates the tank. Water from the base generally means replacement.
05
Condensation
On a cold refill in a humid space, exterior moisture can mimic a leak — the benign explanation worth ruling out.

What you can try yourself

1Identify where the water is actually coming from — top fittings, the valve, or the base of the tank
2Turn off the water supply to the heater at the cold inlet valve above it
3Turn off power at the breaker (electric) or set the gas control to PILOT/OFF (gas)
4Tighten obviously loose fittings gently, without forcing them
5If water is coming from the bottom of the tank, stop — plan for replacement, not repair

When to call someone

Call promptly for any leak from the tank body, any leak you can't isolate, or a T&P valve that keeps discharging.

Who to call

Licensed plumber

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What it should cost

$150–$2,500

Valve and fitting repairs are at the low end. Full replacement including labour, permit and disposal is the top of the range and higher for tankless conversions.

Estimates are typical US ranges for orientation. Actual pricing varies by region, home and contractor — always get a written quote.

What happens if you wait

A tank rupture can flood a garage, basement or living space in minutes, damaging flooring, drywall and belongings. Replacing a failing heater on your schedule is dramatically cheaper than doing it as an emergency after a flood.

Questions to ask the contractor

Is the tank itself compromised, or is this a fitting?
How much life is realistically left in this unit?
Should we add a drain pan and leak sensor?
Is the expansion tank and T&P setup correct?

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