Water Heater Leaking from Bottom: Where is it Coming From?

Water Heater Leaking from the Bottom

If you find that your water heater is leaking from the bottom it could be a serious problem. A pool of water underneath your water heater can often be one of the first signs you notice of trouble. This is a common place to find a leak and should be addressed as soon as possible.

There are several issues that could cause your water heater to leak. A few are fixable. This article will help you identify the problem and give you step-by-step instructions on how to troubleshoot and resolve your leaking water heater.

How to Fix a Water Heater Leaking from the Bottom


Step 1: Find the Leak

Cause #1: Temperature & Pressure Relief Valve

The temperature and pressure relief valve is designed to release water if there's too much pressure inside the tank, or if the water gets too hot. The t/p valve is equipped with a discharge tube that runs from the valve to the floor. The tube is in place to make sure that any water that leaks from the valve is safely directed downwards, towards the floor, rather than outwards where it could be harmful.

If you notice a puddle of water at the bottom of your hot water tank, check the inside of the discharge tube for any moisture. If you find water, the problem is most likely the temperature and pressure relief valve.

The valve is either faulty or there is too much pressure in the tank. This problem is usually fixable by either replacing the valve or calling a plumber to deal with the internal pressure problem.

Temperature and Pressure Relief Valve

Cause #2: Drain Valve

Every water heater has a drain valve at the bottom of the tank. The drain valve is used to drain the tank. It should be drained on a regular basis to remove the sediment that collects within the internal tank. If the sediment isn't drained, it will eventually cause damage to the inside of the tank.

If you notice water pooling around the bottom of your tank you may have a drain valve leak. There are 2 causes to a drain valve leak:

  1. A faulty drain valve
  2. A leaky drain valve

A faulty drain valve will need to be replaced, or you may be able to use a brass garden hose cap to stop the leak until you're able to swap it out with a new one. This article will give you step-by-step instructions on how to change a faulty drain valve.

If you notice water seeping out of the edges of the valve, in most cases the valve isn't water tight and it's simply leaking. Replacing the drain valve will usually solve the problem.

Drain Valve

Cause #3: Internal Tank

Most leaks come from the hot water tank itself. If the tank is leaking, there is an internal problem, and likely one of the components has sprung a leak, causing water to slowly leak out and pool at the bottom of the tank.

Usually, the cause of this is sediment build-up inside the tank. If this sediment is left long enough it will begin to crack and rust the steel tank, eventually leading to a leak.

A leak from the tank itself almost always means the water heater will need to be replaced. In this scenario, you can either contact a professional plumber to investigate further, or you can simply purchase a new water heater.

If you find that your leak is coming from somewhere else, check out our more extensive article to help you troubleshoot.

Preventing a Water Heater from Leaking from the Bottom

Performing regular water heater maintenance will help extend the life of your water heater. Flushing your water heater and checking the anode rod once a year will help prevent sediment build-up, which will, and in turn, extend the life of your water heater.


Step 2: Prevent Further Water Damage

Now that you've located the leak, the next step is to turn off the water and power to the water heater, this will help prevent further water damage.

Refer to your emergency shutdown procedure sticker located on your water heater. If your water heater does not have this sticker, follow these steps:

Turn Off the Power

  • Electric Water Heater - Turn OFF the breaker for the water heater at the main electrical panel. Most water heaters use a 240 volt dedicated circuit breaker, which means that no other appliances will be on the same breaker.
  • Gas Water Heater - Find the on/off dial, located on the side of the water heater near the bottom. Turn the dial to the OFF position.

Turn Off the Water Supply

  • Find the lever or dial located on the water supply inlet.
  • The water supply inlet is located at the top of your water heater. This is where the water enters the tank to be heated.
  • To turn off the water supply, you simply turn the dial clockwise or turn the lever to the closed position (usually parallel to the pipe).
This video will guide you thru troubleshooting your leak, as well as how to turn off your water heater.

Step 3: Decide What to Do Next

Depending on where your leak was, and your comfort level, you may choose to do the repairs yourself, or contact a plumber to make the repairs for you.

If the leak was originating from the temperature/pressure valve, or the drain valve, it's highly likely that your water heater can be repaired.

However, if you find that your internal tank is leaking, you'll most likely be buying a new water heater.  Below you'll find a few of our buying guide resources to help you make an informed purchasing decision:

It's important to keep in mind that water heaters have a life expectancy of up to 10 years, depending on the fuel source. If your water heater is nearing old age, or experiences any of these issues, regardless of the source of the leak, it may be more cost-effective to purchase a new one.