What should I do if my water heater is leaking?

If safe to do so, close the cold-water supply valve and shut off power or gas. Then identify the possible leak area: top fittings, T&P valve, drain valve, or tank body. Fitting and valve leaks may be repairable. Tank body leaks commonly require replacement. Contact a licensed plumber for evaluation.

Can a leaking water heater be repaired?

It depends on the leak location. T&P relief valve, drain valve, and supply connections may be repairable. A leak from the tank body may indicate internal corrosion, and replacement is commonly the practical option. A licensed plumber should confirm the source. Planning ranges vary by repair type and location.

Water heater leaking: what to do right now

Reduce damage, identify possible leak areas, and know when to call a plumber.

Updated April 2026

Do this first: If it is safe to do so, close the cold-water supply valve above the water heater by turning it clockwise. For gas units, turn the gas valve to OFF if you can do so safely. For electric units, shut power off at the breaker only if you can reach it safely. If the unit is electric or water is near electrical components, avoid touching the water heater while standing in water. Shut power off at the breaker only if you can do so safely. If you smell gas, leave the area and contact the gas utility or emergency services. If you are unsure, step away and call a licensed plumber or emergency service professional.

Where is it leaking from?

Top of the unit (supply connections)

Water on top may come from supply connections, fittings, valves, or nearby piping. Avoid disturbing old or corroded parts. A plumber can evaluate the source and determine whether a fitting, connector, or valve needs repair. Planning range: $75–$200.

T&P relief valve (side, with pipe running down)

The temperature-and-pressure relief valve is a safety component. Dripping or discharge may indicate thermal expansion, high pressure, overheating, valve wear, or another system issue. Do not cap, plug, or block the discharge pipe. If the valve is flowing, leaking repeatedly, or releasing hot water, contact a licensed plumber. Planning range: $100–$250 for valve replacement, if appropriate. Pressure-related corrections may cost more.

Drain valve (bottom, with hose bib)

A drain valve can develop a slow drip. Avoid forcing old or corroded valves. A plumber can determine whether the valve can be repaired or replaced. A hose cap may reduce dripping temporarily, but it should not be treated as a permanent repair. Planning range: $75–$200.

Tank body (bottom, pooling underneath)

Water pooling under the tank or coming from the tank body may indicate internal tank failure or another leak source near the base. A licensed plumber should confirm the source. If the tank itself is leaking, replacement is commonly the practical option.

Repair	Cost
Supply fitting repair	$75 – $200
T&P valve replacement	$100 – $250
Drain valve replacement	$75 – $200
Tank replacement (installed)	$800 – $2,500
Tankless replacement (installed)	$1,500 – $4,000

Rumbling or popping can be associated with sediment buildup, especially in older tanks. Ask a plumber whether flushing is appropriate for your unit. If the sounds are new, the unit is older, or you also see rust, leaks, or performance issues, it may be time to discuss repair versus replacement options.

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Based on national trade data and contractor experience. Updated April 2026. All ranges are for planning purposes only — not a quote, diagnosis, inspection, guarantee, or professional recommendation. Actual costs vary by region, access, unit type, plumbing condition, permits, materials, emergency service timing, and contractor. For active leaks, gas concerns, electrical concerns, or hot-water pressure issues, contact the appropriate qualified professional.