Why Is My Tank Water Heater Leaking?

May 26, 2022

Learn how to check what is causing your water heater leak.

Your water heater does the vital job of heating the water you use to shower, cook, clean, and wash your hands. Nobody likes cold showers, so if there’s a problem with your water heater, you’ll likely want to fix it right away.

If you see water leaking from your water heater, it’s a good idea to start investigating. Water heaters are a closed system, so any water outside the tank means something is wrong. Typically, a leak indicates a severe underlying issue that a professional should fix.

Some of the most common causes of water heater leaks are:

  • A cracked tank
  • A deteriorated gasket
  • A faulty Temperature/Pressure Relief (TPR) valve
  • A loose pipe connection
  • An open or worn drain valve
  • High pressure inside the tank

To help you identify the issue and plan your next steps, we’ll explore each of these issues further. However, since water heater leaks can cause water damage, it’s best to call a plumber right away.


Call Red Cap today if your water heater is leaking.

You can depend on us to fix the problem right away. We care for our customers like we do our own family. Call the Red Cap pros at (813) 963-3056 (Tampa) or (727) 474-8287 (Pinellas) or schedule your water heater repair service online.


A Cracked Tank

A cracked tank could be the problem if the water leaks from the side or bottom. This usually happens with older water heaters because the tank’s inner lining corrodes with age. Excess sediment can also build up in the tank’s base, which can speed up corrosion and cause cracks. Alternatively, consistent high pressure inside the tank can produce stress fractures, eventually resulting in leaks.

What to do about it: Unfortunately, once your water heater tank has cracked, there’s nothing a plumber can do to repair it. Instead, they’ll need to install a new water heater. But don’t panic just yet! This is a worst-case scenario, so keep reading to see if another issue is causing the leak.

A Deteriorated Gasket

If you have an electric water heater, the gaskets that hold its heating elements in place can sometimes wear down over time. One of these heating elements is near the top of the tank, and the other is near the bottom. A deteriorated gasket could leave a small hole for water to leak out of, which could explain why your water heater is leaking near the top or bottom of the tank.

What to do about it: If you suspect the leak is due to a worn gasket, call a plumber for help. They can inspect your water heater’s heating elements and replace any worn gaskets.

A Faulty Temperature/Pressure Relief (TPR) Valve

The TPR valve on your water heater is an important safety feature.

If your water heater’s TPR valve isn’t closing properly or is faulty, it could be the source of the leak. But first, we’ll explain why and how this can happen.

The TPR valve is typically on top of your water heater. Or, depending on the model, it could be on the side near the top of the tank. Its job is to ensure that your water heater operates safely by releasing water from the tank to reduce its internal pressure. Over time, a TPR valve can develop a mineral deposit buildup, which can prevent it from closing all the way, allowing water or steam to leak out.

Since the TPR valve is an important safety device, you should address any leaks around it right away!

What to do about it: The best way to determine if the TPR valve is the problem is to contact a plumber. They can inspect the valve and replace it if it’s faulty.

A Loose Pipe Connection

Another possible cause for a leak near the top of your water heater is a loose pipe connection. Your water heater has two pipe connections on top of it: one carries cold water into the tank, and the other delivers hot water to your home’s plumbing fixtures. If these pipe connections are loose or rusty, water can leak from them.

What to do about it: If water appears to be leaking from the connection points of these pipes, you can use a wrench to tighten them. On the other hand, if the connections won’t tighten or the water leaks directly from the pipes, it’s best to contact a plumber for help. They can inspect the pipe connections and repair or replace the leaky pipes.

An Open or Worn Drain Valve

Check that the drain valve is closed if your water heater is leaking.

Your water heater’s drain valve is at the bottom of the tank. If you’ve ever scheduled a water heater maintenance visit, you’ve probably seen the plumber use this drain valve to flush out sediment buildup. Sometimes, if it isn’t closed tightly or the seal around the valve gets worn down due to age, water can leak from or around it.

What to do about it: Make sure the drain valve is tightly closed. If it is, and you still see water leaking out, you should contact a plumber. They can repair or replace the valve for you.

High Pressure Inside the Tank

Pressure building up in your tank water heater can cause a leak.

If the pressure inside your water heater gets too high, it could cause a leak. Here’s how:

When the pressure inside your water heater’s tank gets too high, the TPR valve releases some water to get the pressure back down to a safe level. The water then travels down the side of the tank through the discharge pipe and out through a drain.

If you see hot water constantly draining out of the discharge pipe, it means the pressure inside the tank is too high, and the safety mechanism is at work trying to solve the problem.

What to do about it: You should call a plumber to inspect your water heater and determine what’s causing excess pressure inside the tank.

Need Some Help To Determine the Cause of the Leak? The Experts at Red Cap Can Help

Air Conditioning Technicians in Tampa

Contact Red Cap plumbers for reliable and high-quality tank water heater repairs.

At Red Cap Plumbing & Air, we treat our customers like family with quality water heater repair services. You can trust our experienced team of plumbers to carefully inspect your water heater, diagnose the issue, and give you a fair, upfront price for the repairs. And we always make good on our promises. So if your water heater starts leaking again within a week of our repair, we’ll come back to your home and make it right, free of charge.

If it turns out you need a new water heater, we’ll carefully listen to your needs and wants and recommend a water heater that works for your home and your budget. With our quality installation guarantee, you can expect our plumbers to provide five-star, friendly service that puts your needs first.

Call us at (813) 963-3056 (Tampa) or (727) 474-8287 (Pinellas) or schedule your repair online.


  • Posted in:

Similar Articles: