Even the best water heaters can form leaks, especially as they get older. If yours is leaking, you’ll want to contact a professional to find the source of the leak and fix the problem ASAP.

In this blog, we’ll share what causes your water heater to leak, depending on the type of water heater you have.

If you have a tank water heater, leaks are commonly caused by:

If you have a tankless water heater, the leak could be caused by:

  • Loose or worn-out pipe connections
  • Venting problems (gas units only)
  • Corroded components

Let’s look at each of these problems in more detail below.

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4 reasons your tank water heater is leaking

Tank water heaters are more prone to leaks than tankless units, but the good news is that they are generally less expensive to repair. Let’s look at some common reasons why tank units form leaks.

Reason #1: A pipe connection is loose

See water leaking from the top of the water heater tank?

If so, the cold and hot water inlet pipe connections could be loose.

Water heater showing location of pipe connections

Try tightening the connections with a wrench. If the leak persists, the connection may need to be replaced by a professional.

Reason #2: The drain valve is broken

If the water is coming out of the drain valve (pictured below) at the bottom of the tank, then the valve itself could be faulty.

Water heater drain valve locatoin

After repeated water heater flushes, sometimes the drain valve will not seal shut tightly, which creates a little leak.

If you see water leaking around the drain valve, you should contact a plumber to inspect the valve and replace it if it is faulty.

Reason #3: The pressure/temperature in the tank is too high

Do you see water leaking from a pipe running down the side of the unit? If so, this could mean that your water heater is releasing water to reduce pressure or lower the temperature inside the tank.

We’ll explain: A tank water heater has a safety device called the TPR (temperature and pressure relief) valve. To protect the tank from damage, when the pressure or temperature inside the tank is too high, the TPR valve opens to let out some water. Releasing water brings the pressure levels and temperature back to normal.

The water released by the TPR valve exits out of a discharge pipe that runs down the side of the tank. The discharge pipe drains into a bucket or floor drain. In some homes, the pipe will go through the wall and drain outside.

If you see water coming from the discharge pipe, it’s likely a sign that there’s a pressure or temperature problem with the water heater. A plumber should look at your water heater to determine what’s causing the pressure/temperature problem and then fix the issue. Keep in mind that sometimes there is no temperature or pressure issue and the TPR valve itself may just be going bad and need to be replaced.

Reason #4: The tank is corroded

The worst enemy of a tank water heater is sediment buildup. Over time, minerals and sediments in the water supply slowly corrode the inner lining of the tank, which can eventually lead to a leak.

If you see water leaking anywhere on the tank that isn’t close to a valve or pipe connection, most likely the tank itself has a leak caused by corrosion.

Unfortunately, if the tank starts to leak, there’s not much a plumber can do to repair the leak. In that situation, the best option is to replace the tank altogether. The plumber who installs the new tank can recommend solutions to reduce sediment buildup in the tank so it will last longer.

3 reasons your tankless water heater is leaking

Although tankless water heaters rarely leak (if they’re installed correctly), they can still form leaks for the following reasons:

Reason #1: A pipe connection is loose or worn out

See water leaking from a pipe going in or out of your tankless unit?

If so, the pipe could be faulty. As tankless units age, pipe connections and joints can start to loosen or wear out, causing a leak.

A plumbing professional will need to inspect the piping and tighten any loose connections or replace any faulty pipe components.

Reason #2: Venting problems

Gas-powered tankless units have a venting system, which is used to safely carry harmful gases produced during combustion out of your home.

That said, if the venting system is damaged or disconnected, byproducts from the combustion process (such as water vapor) can leak from the venting system and drip onto your tankless unit or the surrounding area.

If you see moisture dripping from the venting system, you should contact a professional to make sure everything is connected correctly and repair any issues.

Reason #3: Corroded components

Even though it’s less common in tankless units, corrosion can still wear out components inside your tankless unit, creating a leak.

Corrosion in tankless units is typically caused by sediment buildup in the piping or heat exchanger. If the sediment buildup is severe enough, a professional may recommend that you replace the tankless unit altogether.

Want a Buffalo plumber to repair your leaking water heater?

We’ve served Buffalo residents since 1974. Since then, our highly-trained plumbers have repaired countless tank and tankless water heaters. No matter what type of leak you are experiencing, chances are, our plumbers have dealt with it before. We provide professional plumbing services in Buffalo and Western NY, including Amherst, Hamburg, Lackawanna, West Seneca and more.

When you hire Roy’s plumbers for your water heater repair, you can count on world-class customer service and high-quality repairs that will last for years to come.

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