Water Heater Leaking from Bottom (Causes & Solutions) 

In the United States, we enjoy hot water in most buildings without much thought or effort. But when you’re forced to take a cold shower because your water heater malfunctions, it’s quick to grab your attention. 

Water heaters store hot water so that it’s ready to use when you turn the faucet on. Homeowners should inspect these appliances periodically to make sure they are functioning properly.

If you’ve noticed your water heater leaking from the bottom, it’s cause for concern. Luckily, there are troubleshooting steps you can take to correct common problems. 

Malfunctions can arise from loose gaskets, fittings, screws, broken parts, or overflowing expansion tanks. With a little investigation, a few tools, and safety precautions, you can often locate the leak and fix the problem yourself.  

Read below to learn the common causes of water heaters leaking from the bottom. Then, find out how to diagnose and fix your leaking water heater yourself. 

Get your water heater back in working condition today without having to call a plumber.

Common Reasons Your Water Heater is Leaking From the Bottom

Water heaters have a lifespan of around ten years. But if your water heater isn’t too old and you’ve noticed a pool of water around the bottom, you might have a leak. There are several reasons that water heaters begin leaking around the bottom. Let’s look at the common causes of leaks.

The Heating Element Gasket is Loose

Your heating element gasket may be causing your water heater leak.

If you have an electric water heater, it works by using a heating element that’s screwed into the tank. This element warms the water inside the tank. 

The heating element component uses a gasket to seal the opening as it is screwed into the tank. This gasket may become loose. 

Sometimes the gasket is not securely placed when the heating element is initially tightened. Other times, the heating element corrodes or is not properly tightened from the start.

Both cases can cause the gasket to fail to get a good seal. This can lead to water leaking out around the bottom of your water heater.  

Your Fittings are Loose

The fittings connecting your water heater and piping may be leaking.

Water heaters are connected to a water source, either a well or city water. The pipes that run from the source to your water heater are connected to each other with fittings. 

Your water heater also connects to your faucets and other fixtures in your house. Fittings can be made of various materials, including copper, PVC, or brass. 

You can find fittings by looking at the top of your water heater where pipes enter and leave your appliance. If your hot or cold terminals are leaking, you’ll usually see water running down the side of your water heater tank. 

Fittings can leak if they are not properly aligned or sealed. Plumbing fittings may also loosen over time. Additionally, rust and corrosion can compromise the seal at these susceptible joints.

Your Outlet Valve is Broken

Your outlet valve may be leaking.

All water heaters are equipped with a drain valve. This is like an outlet spigot that can be used to empty out your water heater. Reasons to empty your water heater include the following:

  • Cleaning
  • Repairs
  • Replacement

Drain valves are often made of plastic, but are also sometimes metal. They can begin leaking if they are damaged or dislodged. Damage can happen if you bump into the valve. 

The outlet valve can also begin leaking if it is opened and unable to fully close again. For example, if you drain your water heater and then close the valve. Sediment may block the drain valve from closing completely.

The Temperature and Pressure Valve is Broken

Your TP valve may be causing your leak.

Water heaters are equipped with a safety valve called a temperature-pressure (TP) valve. This is an emergency outlet in case the pressure inside your water heater exceeds safe levels.

When the pressure inside your water heater exceeds safe levels, water escapes through the TP valve. However, sometimes water can leak out of this valve even when the pressure inside the system is normal.

A common cause of TP valve malfunction is sediment buildup that prevents a good seal. If your TP valve begins to seep, it will oftentimes keep leaking until it is replaced.

Your Anode Rod Screw is Loose 

Your water heater leak may be caused by anode rods that are loose or due for replacement.

Anode rods are screwed into the top of your water heater. Their job is to reduce corrosion of your tank’s walls by acting as a decoy. Rather than rotting the walls of your tank, the goal is for corrosive agents in your water to attack the anode rod first.

These rods should be replaced every two to four years, depending on your water situation. Harder water may require more frequent replacement. Since these rods screw in, they may become loose and begin leaking before they are due for replacement.

Your Expansion Tank is Overflowing

It’s possible that your water heater leak is caused by an expansion tank overflow.

Homes must have expansion tanks on their water systems to maintain proper water pressure. This lets water in your system expand as it warms up.

It’s common for these expansion tanks to be installed above your water heater. Sometimes these expansion tanks can malfunction and begin leaking.

Leaks can be caused by expansion tanks themselves when faulty fixtures fail. Other times, the temperature-pressure valve will leak because of expansion tank failure. 

Expansion tanks require air in the system in order to maintain proper pressure. If there’s no air inside the expansion tank, then water may leak out of your TP valve when the pressure is too high.

How to Fix Your Water Heater Leaking From the Bottom

Now that you have an idea of some of the causes of a leaky water heater, we can move on to solutions. Minimal tools are required and will be covered below.

In many cases, you’ll want to isolate your water heater from the plumbing system in your home before making any repairs. This includes turning off the power source and possibly emptying the water heater tank.

Below are the steps to follow when fixing water heater leaks. 

Step 1: Shut the Water Heater Off 

While this step may not be required for all repairs, it is never a bad idea to take extra precautions. Turning the power source off to your water heater is simple and quick. 

Shutting the water heater off means that you’re cutting off the power source, either gas or electricity.

Depending on the type of water heater you have, this step will vary. 

  • For electric water heaters: Flip the breaker switch to off
  • For gas water heaters: Turn the knob to “off”

Once you’ve shut off the power source to your water heater, you may need to wait for the unit to cool down before the piping and other parts are safe to touch. 

Step 2: Turn off the Cold Water Intake

Remove pressure from your water heater by isolating the system. This is done by turning off the cold water intake valve. 

The cold water intake valve can usually be found attached to one of the pipes coming into your water heater from the top. Turn the lever so that it is perpendicular to the pipe.

Alternatively, you can shut the water off to your entire house. From there, open a fixture in your house (such as the kitchen sink turned to hot water) to relieve the pressure in the lines.

Once you’ve removed all of the pressure, you may need to drain your water heater by connecting a garden hose to the drain outlet. The water from inside your tank will drain out.

Step 3: Find the Source of the Leak 

Finding the source of a leak from your water heater can be tricky. To begin, dry off any wet or damp areas so that you can see where water returns. 

It’s not uncommon for water heaters to leak around the TP valve, drain valve, or the fixtures that connect to the water heater. Identify the source by following the instructions below.

Check Pipes and Fittings

To check pipes, fittings, and anode rod for leaks, simply dry off the pipes and connectors that attach to your water heater. Take caution to check the temperature before touching any hot pipes.

After drying these connections, inspect them carefully to see if water reappears. If you find water, you have a leak. In this case, your best course of action is to call a licensed plumber to repair. If your anode rod is leaking, you may be able to replace it yourself.

Check Your Temperature and Pressure Value

TP valves should be replaced every five years. If you have water pooling at the base pipe where your TP valve connects, then your temperature-pressure valve may need to be replaced.

You can do it yourself or have this job completed by a licensed plumber.

Check the Heating Element Gasket 

If your heating element gasket is leaking, you’ll find water leaking out around the area that the heating element screws into the tank. 

You may be able to tighten the heating element with a special wrench or large channel locks by rotating clockwise. If that doesn’t work, replace the heating element with a new gasket. 

This can be done as a do-it-yourself project or by a plumber.

Check the Expansion Tank

Expansion tank leaks can be identified by water leaking out around the fixtures nearby the expansion tank. A malfunction can be harder to pinpoint if the water leaks out through the pressure valve instead.

Expansion tanks require air to properly pressurize the system. You can recharge the air in your expansion tank by adding air into the air valve with an air hose. 

If this doesn’t solve the leak at your expansion tank or TP valve, call a licensed plumber to look further into the cause.

Step 4: Reconnect the Water and Turn the Water Heater Back on

Once you’ve found the leak and repaired it, you can turn the water valve back on. After water pressure is restored, reignite your gas water heater or turn the breaker back on to your electric water heater. Continue to monitor for leaks.

When Should You Call a Professional?

If none of the diagnostic steps above identifies or resolves your problem, then it’s time to take it to the professionals. Plumbers often charge a minimum of $100 for a service call, plus parts and labor. Water heater repair costs vary from $200 to $1,000 on average.


Discovering a leak near your water heater is scary. Often, finding the leak is the worst part. Whether it’s your water heater or another major household appliance, always check for DIY solutions before calling in expensive professionals. The solution may be simpler than you imagined.

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