Why Is My Water Heater Leaking? Common Causes & How to Fix It – 2025

Common Reasons for a Leaky Water Heater:

• Cracked or Corroded Water Heater Tank: Over time, tanks can develop cracks or corrosion, leading to hot water tank leaks.
• Loose or Faulty Fittings and Pipe Connections: If the fittings or connections around the tank are loose or damaged, they can cause water to leak from the inlet, outlet, or other joints.
• Improperly Installed Temperature and Pressure Relief Valve: If the PRV isn’t installed correctly, it may not function as intended, resulting in leaks or water discharge.
• Worn Out Anode Rod: The anode rod helps protect the tank from corrosion. If it’s worn out or ineffective, it can cause the tank to corrode and eventually lead to leaks.

Identifying the leaks:

The first step in fixing a hot water tank leak is identifying the source of the leak. Check whether the water heater is leaking from the bottom or the top. The leak could be coming from a faulty valves, a loose supply line connection, or the discharge pipe.

To find the source of the leak, use a bright light to thoroughly inspect the area.  If you have an HVAC unit nearby, be sure to check around it as well, as it could be contributing to the water leaks. Taking the time to inspect every possible source will help you pinpoint the problem more efficiently. Here, we will go over how to inspect every part of your hot water heater and some ideas for fixing any issues.

Safety First:

Before starting any repairs, always de-energize the system to prevent hazards.

• Turn off the electric power supply at the main breaker panel if you have an electric water heater.
• Shut off the gas valve if your water heater is gas-powered.
• Close the water supply line to stop additional water from entering the tank.

Taking these precautions ensures a safe and controlled repair process.

Inspect the Top of the Hot Water Heater :

Start by inspecting the top of the tank where the inlet and outlet lines are connected. Pay close attention to the joints and couplings, as these are common areas for hot water tank leaks. If you notice any water around these joints or spill water near them, it’s a clear sign that the water heater is leaking.

Also, check the anode rod inside the tank. While a rusted or corroded anode rod won’t directly cause a leak, it can contribute to corrosion inside the tank, which could eventually lead to leaks over time. Replacing a worn-out anode rod can help extend the life of your water heater and prevent future. Anode rode can be found in top as well as bottom on side of tank.

Fixing the Leak from Top of Hot Water Heater:

• If the leak is coming from a threaded joint, try tightening it slightly. Be careful not to overtighten, as this could cause damage to the threads.
• In some cases, open the joint completely, clean it, and then reattach it using pipe dope and plumber’s tape to ensure a tighter seal. Only do this if you have the proper tools and feel confident in your ability to do it safely.
• If Leaking for Anode Rod, With the water and electricity off, unscrew the rod’s hex head, which is situated on the top of the tank, using a 1/16-inch socket. Remove the rod from the tank. Replace it with a new one, readily available at most hardware and home improvement stores, if it has shrunk to 12″ or less in diameter. Teflon tape should cover the thread before securing the replacement rod with screws.

If the joint is soldered and it’s leaking, it’s best to call a professional plumber to repair it, as soldered joints require specialized skills and tools to fix properly.

Inspect the Side of the Hot Water Heater:

Inspect the side of the water heater for any visible issues. One common feature you’ll find is the pressure relief valve, which helps prevent pressure buildup in the tank by releasing water if the pressure gets too high. This is a normal function, and we’ll cover it in more detail in the next step.

While inspecting the side, also check for any bends or cracks in the tank. If you find a crack or bend that’s causing the hot water tank leaks, the only permanent solution is to replace the tank. However, for temporary relief, you can use strong water seal tape to stop the leak. Just make sure that the tape you’re using can handle the high temperatures of the tank to avoid further issues

Inspect the Pressure Relief Valve (PRV):

The pressure relief valve (PRV) is a major component of your water heater. Its function is to release water if the pressure inside the tank exceeds safe levels.  This is usually on side in top section of hot water tank. If your PRV is dumping water, it could be due to excessive pressure or temperature.

Fixing the Issue:

• First, check the temperature setting on your water heater. Ensure it’s set to the recommended 120-140 degrees Fahrenheit. If the temperature is too high, it could cause the PRV to release water.
• If the temperature is properly set and the PRV is still leaking, there’s no need to replace the tank. In this case, you can replace the PRV itself. It’s a relatively simple fix, but if you’re not comfortable doing it yourself, it’s best to call a reliable plumber to have it replaced professionally.

Inspect the Bottom of the Water Heater:

The bottom of the water heater is where most people spot leaks. At the bottom, you’ll find a small drain valve, which is used to drain a hot water heater for cleaning and flushing the tank. If you notice any moisture or water droplets around this valve, it may indicate that the valve isn’t closed properly, the joint is loose, or the valve has corroded or broken from the inside.

Fixing the Leak:

• First, close the valve properly and tighten it slightly—be careful not to overtighten, as that could cause damage. After tightening, check if the leak stops.
• If tightening doesn’t solve the problem, it could mean that the threads on the valve are damaged. In this case, the drain valve will need to be replaced.
• Replacing a drain valve can be a tricky job, and if you don’t have the right tools, it’s highly recommended to call a local plumber to ensure the job is done properly.

Not Sure of the Source of the Water Heater Leak?

If you can’t find a clear source for the leak, it could be condensation causing water to gather around the hot water tank. This is especially common if you have installed water heater is in a cold room.

To test for condensation, wipe up any water around the floor and the hot water heater. Wait a while and check again. If you notice water droplets forming on the tank, pipes, or surrounding areas, it’s likely condensation.

What to do if condensation is causing the leak:

• Relocate the water heater to a room or area with a more stable, warmer temperature.
• Another option is to add insulation around the pipes and the tank to help prevent condensation from forming. This will reduce the chance of a leaky hot water tank caused by temperature differences.

You may also like : How to drain hot water heater 

Call Everest Drain & Plumbing for Expert Water Heater Leak Detection & Repair!

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FAQ's of Leak Water Heater

Is a leaky hot water heater dangerous?

Yes, a leaking water heater can cause water damage, mold growth, and even pose a risk of explosion if the pressure builds up too high.

Can I take a shower if my water heater is leaking?

It’s not recommended. Depending on the cause, using the heater could make the leak worse or lead to safety issues.

What should I do when my hot water heater is leaking?

Turn off the water supply, shut off power or gas, and call a professional plumber to assess and fix the issue.

Is a leaking hot water heater an emergency?

Yes, a leaky hot water tank can cause major water damage if left untreated. Call a plumber immediately to prevent costly repairs.

How much does it cost to replace a hot water tank?

The cost ranges from $1,200 to $2,500, depending on the size, brand, and installation requirements.

Is it cheaper to repair or replace a hot water tank?

If the issue is minor, a repair is more affordable. But if the tank is old or leaking from the bottom, replacement is the best option to avoid future problems.

How long does it take to replace a hot water tank?

A professional plumber can usually replace a water heater in 2-4 hours, depending on the complexity of the installation.

How do I know if my water heater needs replacement?

Signs include rusty water, frequent leaks, strange noises, or water not heating properly. If your heater is over 10-12 years old, consider replacing it.

Can I replace my hot water tank myself?

It’s not recommended. Water heater installation involves gas, electrical, and plumbing work, which should be handled by a licensed plumber to ensure safety and compliance with local codes.

Does Everest Drain & Plumbing replace hot water tanks?

Yes! Everest Drain & Plumbing provides professional water heater replacement and installation services across Toronto and the GTA.