Why Is My Hot Water Heater Leaking?

Did your water heater mysteriously start leaking? This is frustrating for any homeowner, but the good news is that most leaks start small and can be easily fixed if you act quickly. The solution may be as simple as tightening a few loose connections or valves.

However, a water heater leak can sometimes indicate a larger problem. If rust or corrosion is at play, it may be time to replace your water heater altogether.

This guide covers the most common causes of water heater leaks, what they mean and what homeowners should do about them.

Why Is My Water Heater Leaking?

The first step in fixing a leaking water heater is to determine the cause of the leak. This is easier said than done, since water heaters can leak for a variety of reasons. They can range from easy-to-fix problems to more serious issues.

Most water heater leaks begin slowly and worsen over time. If you catch a leak early and act quickly, you can get to the root of the problem and find a solution before it gets out of hand.

Some of the most common reasons water heaters leak include:

• Loose or malfunctioning valves
• Your water heater needs an expansion tank
• Sediment buildup inside the tank
• Your water heater needs to be replaced

Let’s dive more into these.

Loose or Malfunctioning Valves

Water heaters have two main valves: the temperature and pressure relief valve and the drain valve. Over time, these valves can loosen, corrode or fail due to wear and tear. 

A faulty valve can cause small but steady drips to leak from your water heater. It may also cause your water heater to start tripping your breaker. 

If a loose or malfunctioning valve is the cause of your water heater leak, the first step is to tighten the valve gently with a wrench. You should also make sure that your drain valve is completely closed. These steps may be enough to stop the leak altogether. 

If the valves continue to leak even after you tighten them, it’s time to call in a plumber.

Your Water Heater Needs an Expansion Tank

Water expands as it heats up, and if you have a closed plumbing system, it’s possible that the water simply has nowhere else to go. When this happens, the water is forced out of the temperature and pressure relief valve, along with other small cracks in the system.  

If water tends to leak from your system as it’s heating up, that’s a sign that the tank is too full. The good news is that there’s an easy fix. You will just need to have a plumber install an expansion tank to give the water somewhere else to go. This will stop the leak and help your system function properly again.

Selecting the correct size expansion tank is important, which is another reason why it’s best to leave this task to the professionals. Call in a plumber to inspect your system, recommend the right expansion tank and install it for you.

Sediment Buildup Inside the Tank

If your heater is more than a few years old, the cause of the water leak could be sediment buildup. Minerals from hard water settle at the bottom of your water heater over time. 

The more minerals that build up, the harder it becomes for your heater to warm the water efficiently. This can cause overheating, cracks and corrosion in the lining of the water tank. A common sign of sediment buildup is when your water heater makes noise.   

Sediment buildup is a common issue that can cause leaks and reduce the efficiency of your water heater. A licensed plumber can flush the tank, remove mineral deposits and check for signs of corrosion. Regular professional maintenance, about once every six months, helps prevent leaks and extend the life of your water heater.

Your Water Heater Needs to Be Replaced

While it’s not the best news, a leak can indicate that it’s time to replace your water heater. This is especially common with older heaters that have endured years of wear and tear.

If your water heater is more than eight years old, the problem is likely that the tank is corroding from the inside. Once the inner lining of the tank begins to deteriorate, it’s time to replace your system.

How do you know if this is happening to your water heater? The most obvious signs are noticing pooling water at the base of the unit, rust on the bottom or sides of the tank and a metallic odor or reddish tint to your hot water.

The best course of action is to consult with a professional plumber. They can advise you on whether your system can be repaired or if it’s time to replace your water heater.

What Should I Do If My Water Heater is Leaking?

If your water heater is leaking, call in a plumber to inspect your system and find the cause of the leak. However, there are some simple troubleshooting tasks you can try on your own.

1. First, turn off the power to your water heater. You should also turn off the cold water supply to stop the flow of water into the heater. 
2. Next, try to identify the source of the leak. The most common causes of water heater leaks are loose connections, loose or faulty valves and tank corrosion. If a connection or valve is loose, try tightening it with a wrench and see if the leaking stops.
3. You can control the leak damage by drying the pooled water with towels or a wet/dry vacuum. You should also place a bucket below the drip to catch the water.
4. Finally, if tightening loose connections did not stop the leak, call in a plumber to inspect your system.

Water Heater Leaks: DIY Fix or Call in a Pro?

Why is My Water Heater Leaking From the Bottom?

If your water heater is leaking from the bottom, you likely have an issue with your drain valve, temperature and pressure relief valve or a failing internal tank. The fix may be as simple as tightening a valve.

However, if that doesn’t work, you’re likely dealing with a corroded water tank. This is not an easy fix and requires professional experience.

Why Does My Water Heater Leak Occasionally?

Does your water heater leak only occasionally, rather than consistently drip? This is likely due to high water pressure, a malfunctioning temperature and pressure relief valve or loose connections.

To get to the bottom of the mystery leak, turn off the power to the water heater and look at all of the heater’s components for signs of damage, leaks or loose parts. Tightening loose connections with a wrench may solve the problem for you.

However, if the leak persists, call in a plumber to inspect your water heater. They can pinpoint where it’s coming from and offer an expert recommendation about what to do next.

Frequently Asked Questions About Water Heater Leaks