Water Heater Leaking? What to Do Right Now

A puddle around the water heater is one of the most common plumbing calls. Sometimes it is a loose fitting. Sometimes the tank is failing and could release much more water. Acting fast limits damage, especially if the heater sits in a finished basement or a closet above living space. This guide walks you through the first steps. For repair or replacement, see our water heater repair in McLean service.

This is general information. Follow the safety instructions on your heater's label.

What should I do first?

Turn off the energy. Electric: switch off the breaker. Gas: turn the gas control to off or pilot, following the label.
Close the cold water supply valve at the top of the heater.
Catch and move water away from belongings and floors.
Do not touch hot surfaces or water near electrical parts.
If it is spraying or making loud noises, keep people away and close the main water shutoff.
If you smell gas, leave the house and call 911 and Washington Gas from outside.

Where is the leak coming from?

Where you see water	Likely source	Usually repair or replace?
Top of the heater	Loose inlet or outlet connection, or a failed fitting	Repair
Relief valve pipe	Valve opening from high temperature or pressure, or a bad valve	Repair; may need expansion tank
Drain valve near the bottom	Loose or failed drain valve	Repair
Under the tank with dry fittings	Tank corroded through	Replace
Water in the burner area (gas)	Condensation or a tank leak	Diagnose
Damp but no drip	Condensation on a cold tank	Often normal

Why do water heaters leak?

Corrosion. The anode rod wears away over time. Once it is gone, the steel tank begins to rust.
Sediment. Minerals build up on the tank bottom, cause overheating and stress the tank.
High pressure. Without room for water to expand as it heats, pressure rises and the relief valve may open.
Loose fittings. Connections can loosen with heat cycles.
Age. Older heaters are more likely to leak from the tank.

Is it time to replace the water heater?

Replace the heater if the tank itself is leaking. Consider replacement if it is old, has rusty hot water, makes loud popping sounds, or has needed several repairs. Repair makes sense when the tank is sound and the leak is at a valve or fitting.

What does Fairfax County require?

Fairfax County's Household Appliance permit covers replacing appliances in a home, and the county states that gas water heater replacement requires a permit even when it is like-for-like. If new gas piping is needed, a residential plumbing permit applies instead. A plumber should tell you which permit your job needs.

What about insurance?

This is not insurance advice; every policy differs. Virginia's Bureau of Insurance consumer guide tells homeowners to give immediate notice of a possible claim, protect the property from further damage and keep records of emergency repairs. Many policies treat sudden discharge of water differently from a worn-out appliance, so check your coverage.

How do I prevent water heater leaks?

Flush the tank to remove sediment, following the manufacturer's guidance.
Have the anode rod checked every few years.
Test the relief valve as the label directs.
Install an expansion tank if pressure is high.
Put a drain pan and a leak sensor under heaters above finished space.
Check around the heater monthly for drips or rust.

The EPA's WaterSense program notes that even small household leaks add up to more than 9,300 gallons a year in the average home, so a small drip at the heater is worth fixing.

Local note: Basement water heaters are common in Vienna and Oakton homes. Many Reston and Herndon townhomes have heaters in closets or garages, where a drain pan matters. Tysons condos often have heaters in small closets above another unit.

Related reading: Learn how to prevent frozen pipes, read our ceiling leak guide, and see what sets leak detection cost.

When should you call a plumber?

Call when the tank itself is leaking, when the relief valve keeps releasing water, when you cannot find the source, or when the heater is old and showing rust. Call right away if water is spreading into finished space.

Water heater leaking in McLean? Call (571) 760-4451 for 24/7 water heater repair from McLean Plumber Works.

Frequently asked questions

Is a leaking water heater dangerous?

It can be. Water near gas burners or electrical parts is a hazard, and a failing tank can release a lot of water. Turn off the power or gas and the cold water supply, and keep people away from a heater that is spraying or making loud noises.

Why is my water heater leaking from the bottom?

A loose drain valve, condensation or water running down from a fitting above can collect at the bottom. A leak from the tank itself, usually from rust, means the heater needs replacing.

Why is water coming out of the relief valve pipe?

The temperature and pressure relief valve opens when the tank is too hot or the pressure too high. It can also fail and drip. High pressure may call for an expansion tank.

Can a leaking water heater be repaired?

Leaks from valves, fittings and connections can usually be repaired. A leak from the tank body cannot; the heater should be replaced.

Do I need a permit to replace a leaking water heater?

In Fairfax County, a gas water heater replacement requires a permit even for a like-for-like swap. Ask about the rules for electric units.