How to Troubleshoot a Leaky Water Heater

A leaky water heater can be a nuisance, causing damage and driving up utility bills. Fixing the leak yourself can save money on repairs. With some basic troubleshooting, you can often resolve the issue and stop the drips.

Signs of a Leak

The first step is identifying if you actually have a leak. Some signs include:

  • Visible water on the floor around the heater
  • New moisture or rust stains on the heater or nearby walls/floor
  • An audible hissing or dripping sound coming from the tank
  • Reduced hot water pressure
  • High utility bills

If you notice any of these, it likely indicates a leak. Pinpointing the exact source will help troubleshoot the problem.

Locating the Leak

Check connections and supply lines: Examine all water lines and fittings connected to the water heater. Look for wet areas, mineral deposits, or corrosion which indicate leaks at joints.Leaks commonly occur at the cold water inlet, hot water outlet, T&P relief valve, or drain valve.

Inspect the tank: If pipes are dry, the leak may be from the tank itself. Rust spots, mineral deposits, or water stains identify the area. Small leaks may not be visible so you need to closely examine the entire surface.

Leak detector: For very slow leaks, you can use a leak detector liquid or device to pinpoint the exact spot. These will react or alarm at the source.

Pressure test: Isolating the tank and performing a pressure test with water or air can also locate leaks. Watch for drops or falling pressure.

Identifying the leak source is key to targeting your repair efforts.

Common Causes of Water Heater Leaks

Once you’ve spotted the leak, understanding what’s causing it will help troubleshoot the issue:

Faulty Temperature and Pressure Relief Valve

The T&P valve is a crucial safety device that opens to release excess heat and pressure. However, debris can jam it open leading to leaks. Inspect the valve and test lifting the lever yourself. Replace it if needed.

Corroded/Damaged Water Connections

Age, mineral deposits, or high water pressure can corrode pipes and fittings. Check supply lines, nipples, and valves for wear. Replace any visibly damaged parts.

Tank Rust and Corrosion

Internal corrosion causes rust and small perforations in the tank allowing water to seep out. Inspect for rust spots or mineral stains on the exterior. If the tank is 6-10 years old, corrosion is the likely culprit.

Sediment Buildup

Scale and sediment settling at the bottom can lead to leaks as it corrodes the tank from inside. Drain and flush the tank to clear out deposits.

High Temperature/Pressure

The tank temperature or water pressure exceeding safe levels stresses components leading to leaks. Adjust your thermostat and pressure reducing valve accordingly.

Loose Fittings/Joints

Fittings can loosen over time and should be checked for tightness. Re-tighten or use pipe thread sealant to stop leaks at joints.

Finding the root issue guides you toward the proper repair method.

How to Stop a Leaking Water Heater

Stopping a leak involves pinpointing the source then implementing the appropriate fix:

Leaking Valves and Fittings

  • Tighten fittings and valves. Use pipe thread sealant tape or compound on threads.
  • Replace worn gaskets, washers, and o-rings.
  • For a leaking T&P valve, lift and reset lever. Replace if needed.
  • Swap out any visibly damaged pipes, nipples, elbows, and couplings.

Leaking Tank

  • Drain and flush sediment. Scale removal products can help.
  • Patch small holes using a water heater specific epoxy resin patch kit.
  • Replace anode rod if corroded. Helps protect against rust.
  • Consider adding a water softener system to reduce mineral deposits.
  • If the leak is severe or tank aged over 10 years, replacement may be necessary.

Leaking Water Connections

  • Examine supply lines and fittings for damage. Replace any worn parts.
  • Verify water pressure doesn’t exceed 80 PSI. Install a pressure regulator if needed.
  • Upgrade to braided stainless steel supply hoses less prone to leaks.
  • Ensure fittings are tightened properly. Use pipe sealant.

Persistent Leaks

For difficult leaks that resist basic fixes, call a plumber. A professional has specialized tools and expertise to fully diagnose and repair the system.

Stopping the leak quickly is important to prevent water damage and unsafe conditions.

Safety Precautions

When troubleshooting a water heater leak, keep these safety guidelines in mind:

  • Turn off power/gas to water heater before starting repairs.
  • Shut off incoming water supply and drain tank if needed.
  • Beware of hot surfaces. Allow to fully cool before working.
  • Use caution handling pressurized water lines. Release pressure before disconnecting.
  • Have a bucket and towels ready to catch/clean up water spillage.
  • Wear eye protection when working below leaky valves/fittings.
  • Use gloves and long sleeves when tank cleaning. Rust can be sharp.
  • Refer to manufacturer instructions for proper operation and settings.
  • Seek assistance if not comfortable performing electrical/gas repairs.

Exercising caution helps avoid injury or additional issues. Call a professional for complex repairs.

Preventing Leaks

You can take proactive measures to help avoid leaks and maximize your water heater’s lifespan:

  • Flush the tank annually – Removes sediment that can corrode the tank.
  • Inspect anode rod – Replace if corroded. Helps protect interior from rust.
  • Check pressure and temperature settings – Confirm within operating limits.
  • Update supply lines – Replace old hoses with new braided stainless steel.
  • Watch for leaks – Periodically examine for drips, rust, or moisture.
  • Adjust water softener – Soft water reduces scale/mineral buildup.
  • Keep connections tight – Tighten fittings that may vibrate loose over time.

Routine maintenance helps your water heater operate safely for years before leaks develop.

When to Call a Professional

While many leaks can be addressed DIY, some scenarios require a trained plumber:

  • Leak source cannot be located
  • Tank leaks below water line or from multiple spots
  • Significant corrosion damage to tank
  • Leak persists after troubleshooting fixes
  • Water connections inaccessible or complex
  • Electrical/gas system repairs needed
  • Lack proper tools or comfort level for repairs

A qualified plumber has the expertise to fully diagnose your system and repair complex issues. For extensive leaks or tank replacement, professional service ensures proper installation for safety and performance.

FAQs About Water Heater Leaks

What are signs my water heater is leaking?

Common signs include water puddles on the floor, new rust stains on the tank, reduced hot water pressure, loud dripping noises, and higher utility bills.

Where do leaks typically occur?

Leaks often develop at the cold water inlet, hot water outlet, T&P relief valve, drain valve, and tank fittings. Supply lines, pipe joints, and the tank itself can also leak.

Can I patch a small leak in my water heater tank?

Yes, minor leaks from small perforations or holes under 2 inches can often be temporarily patched using water heater epoxy sealant kits. Follow kit instructions closely.

Is it worth repairing an older leaking water heater?

If your tank is over 8-10 years, it may be nearing the end of its lifespan. For major leaks or corrosion on an aged unit, replacement is usually the better option vs. sinking money into repairs.

When should I call a professional for a leak?

Contact a plumber if you can’t locate the leak, the fixes are beyond your skill level, leak persists after troubleshooting, or the tank needs replacement. Let the pros handle complex repairs.


Dealing with a leaky water heater can be frustrating, but is usually repairable with some basic troubleshooting. Follow these steps:

  • Inspect and locate the source of the leak.
  • Identify what’s causing the issue.
  • Implement targeted fixes like replacing worn parts, adjusting settings, cleaning, or patching.
  • Exercise proper safety precautions during repairs.
  • Consider preventive maintenance to help avoid leaks.
  • Call a professional plumber for complex repairs or replacement needs.

With the right approach and some DIY repair skills, you can often resolve a water heater leak yourself and restore reliable hot water to your home. But don’t hesitate to call in a pro for backup when needed.