Water Heater Leaking? Here's What to Do

Published: February 12, 2024

Discovering water pooling around your water heater is alarming. A leaking water heater can cause significant water damage and create safety hazards if not addressed promptly. This guide walks you through immediate steps to take, common causes of leaks, and when you need professional water heater service.

Immediate Steps: Shut Off Everything

When you discover a leak, act immediately to prevent further damage:

Step 1: Turn Off the Power

For electric water heaters: Go to your circuit breaker panel and flip the breaker for the water heater to the "off" position. Never work on an electric water heater that's still powered.

For gas water heaters: Locate the gas control dial on the front of the unit and turn it to the "off" position. This stops the burner from operating while you assess the situation.

Step 2: Turn Off the Water Supply

Locate the cold water inlet valve above your water heater (usually a gate valve or ball valve on the cold water pipe). Turn it clockwise until fully closed. This stops additional water from entering the tank and worsening the leak.

Step 3: Drain the Tank (If Necessary)

If the leak is severe, draining the tank prevents further water damage. Connect a garden hose to the drain valve at the bottom of the tank and run it to a floor drain or outdoors. Open the drain valve and let water flow until the tank empties. Our guide on how to drain a water heater provides detailed instructions.

Identifying the Leak Location

Finding where the water is coming from helps determine the severity and appropriate repair.

Leaking from the Bottom

Water at the base is the most concerning scenario:

• Tank leak: Internal corrosion created a hole in the tank. This requires replacement.
• Drain valve: The drain valve may be loose or faulty. Tighten or replace it.
• T&P valve pipe: The discharge tube from the temperature and pressure relief valve may be leaking.

Leaking from the Top

Top leaks are often repairable:

• Inlet/outlet connections: Loose fittings at the cold water inlet or hot water outlet
• T&P valve: Faulty temperature and pressure relief valve
• Internal tank leak: Water travels down the side from an internal failure

Leaking from Sides

Water running down the tank exterior usually indicates a leaking fitting or seam. This often means the tank itself is compromised and requires replacement.

Common Causes of Water Heater Leaks

1. Tank Corrosion and Failure

Over time, internal corrosion eats through the tank lining. When the anode rod depletes completely, corrosion attacks the tank steel. The result is a pinhole or larger breach that allows water to escape. This is a sign your water heater needs replacement.

2. Faulty Temperature and Pressure Relief Valve

The T&P valve is a safety device that releases pressure if temperature or pressure exceeds safe limits. If it's:

• Leaking continuously: Replace the valve
• Opening frequently: The temperature setting may be too high, or there's a pressure problem in your water system

3. Loose or Worn Drain Valve

The drain valve at the bottom of the tank can loosen over time or develop a leak from mineral deposits in the seals. Tightening the valve may resolve the issue. If not, valve replacement is a simple and inexpensive repair.

4. Damaged Inlet or Outlet Connections

Connections where water enters and exits the tank can develop leaks from:

• Loose fittings
• Damaged threads
• Worn gaskets or washers
• Corroded pipes

5. Sediment Buildup

Sediment accumulation causes overheating, which stresses the tank and can lead to cracks. Regular flushing prevents this problem.

6. Condensation

In some cases, what appears to be a leak is actually condensation. When a tank fills with cold water and heats up, condensation can form on the outside and drip down. This typically resolves on its own as the tank warms.

7. High Water Pressure

Excessive water pressure can stress all components of your plumbing system, including the water heater. If your T&P valve frequently releases water, have your home's water pressure checked. It should be between 50-80 PSI.

Repair vs. Replacement

Whether to repair or replace depends on the leak source and your water heater's age:

When Repair Is Possible

• Loose inlet/outlet connections
• Faulty T&P valve
• Leaking drain valve
• Damaged pipes or fittings

When Replacement Is Required

• Leaking from the tank itself
• Tank corrosion and failure
• Unit is over 10 years old with a leak
• Multiple repair issues suggesting systemic failure

Review our guide on water heater lifespan to assess whether your unit is nearing replacement age.

Preventing Future Leaks

Regular maintenance significantly reduces leak risk:

Annual Inspections

Have your water heater inspected yearly for signs of corrosion, leaks, and component wear. Catching problems early prevents catastrophic failures.

Anode Rod Replacement

Replace the anode rod every 3-5 years. This sacrificial rod attracts corrosion away from your tank and prolongs its life.

Regular Flushing

Flush your water heater annually to remove sediment that causes overheating and corrosion.

Test Your T&P Valve

Manually test the temperature and pressure relief valve once a year. If it doesn't operate smoothly, replace it.

Install a Drain Pan

A drain pan under your water heater catches small leaks before they become big problems. Route the pan's drain line to a floor drain or outdoors.

Water Damage Prevention

If your water heater leaks, act quickly to minimize damage:

• Shut off water at the main valve if you can't stop the tank leak
• Remove standing water promptly to prevent mold growth
• Use fans and dehumidifiers to dry affected areas
• Document damage for insurance claims with photos
• Check nearby drywall and flooring for water damage

When to Call a Professional

While some repairs are DIY-friendly, many leak situations require professional help:

• Leaking from the tank body—requires immediate replacement
• Gas water heater valve or line issues
• Electrical problems with electric water heaters
• Uncertainty about the leak source
• Water heater over 8 years old with any leak

Know when to call a water heater professional to ensure safety and proper diagnosis.

Emergency Steps Summary

If your water heater is leaking NOW:

1. Turn off the power (breaker for electric, gas valve for gas)
2. Turn off the cold water supply valve above the tank
3. Connect a hose and drain if necessary to stop active leaking
4. Identify the leak source
5. Call for professional help if the tank is leaking

Don't wait to address a water heater leak. Small leaks become big ones, and water damage escalates quickly. Contact a water heater professional today for leak diagnosis and repair.