Why My Water Heater Leaks?

Aug 03, 2023, 12:23pm

There are many models of water heaters: there are, for example, electric, thermodynamic or even solar water heaters. These three models have a specific way of generating the necessary energy and supplying a house with hot water.

When you notice a leak on your water heater, it may be due to:

  • tank,
  • of the security group,
  • of the electrical group
  • or fittings.

Water heater leaks can lead to significant water damage in your home if not addressed promptly. Understanding the root cause can help you take appropriate action and prevent such scenarios. This article explores several reasons why your water heater may be leaking.

Why My Water Heater Leaks?

1. Faulty Drain Valve

One of the most common reasons for a leaking water heater is a faulty drain valve. This valve, located at the bottom of the tank, allows for the drainage of water for maintenance or replacement. If it is loose or defective, it can cause a leak. A slight tightening might solve the problem, but if it continues to leak, you may need to replace the valve.

2. High Pressure

If the pressure inside your water heater tank becomes too high, it can cause the water to leak out. This excessive pressure can be due to the temperature being set too high or due to a faulty temperature and pressure relief valve (T&P valve). Lowering the temperature or replacing a malfunctioning T&P valve can remedy this situation.

3. Internal Tank Leak

Water heaters have an internal tank that holds the water to be heated. Over time, this tank can corrode and develop small cracks, leading to a leak. Unfortunately, if your tank is leaking, it often means that it’s time to replace your water heater.

4. Corroded Anode Rod

The anode rod in your water heater serves a crucial function: it attracts corrosive elements in the water, protecting the tank from rust. However, over time, this rod itself can corrode. If not replaced, those corrosive elements can attack the tank, leading to leaks. Regular inspection and replacement of the anode rod can prevent this issue.

5. Faulty Inlet or Outlet Connections

Leaks can also occur if the inlet (cold water) or outlet (hot water) connections are loose or faulty. Check these connections to see if they need tightening or replacement.

6. Condensation

Sometimes, what appears to be a leak might actually be condensation on the outside of the tank. This can occur if cold water enters the tank in a hot, humid environment, causing condensation to form. If this is the case, the “leak” should disappear as the water inside the tank heats up.

Why My Water Heater Leaks?


Your safety group is an important part of your water heater because it allows you to empty it.

  • If you notice regular dripping from your safety group while heating, then everything is working fine.
  • However, if the drip is not regular and you see a trickle of water, then the water pressure is too high.
  • If your security group is leaking after hours (out of business hours), then it’s either a failure or a pressure issue.


If you find that your safety box is leaking after hours, it may be defective or there is a pressure problem.

  • Find your valve to close it and see if water is flowing.
  • If the water has stopped flowing, the problem with the leak is due to a pressure problem. Have a professional check the pressure in your water supply.
  • If water is still flowing after closing your valve, your safety group is faulty and needs to be replaced.


Water heater leaks can range from simple issues with an easy fix, such as tightening a valve, to complex problems requiring a complete replacement of the water heater. If you notice your water heater leaking, it’s best to address the problem immediately. If you’re uncomfortable handling it yourself, call a professional plumber to diagnose and fix the issue.