Main Causes of Water Heaters Leaking 

Leaks, even the most minor ones, cannot be ignored. They are always signs of a problem and will only worsen over time. Water damages floors, furniture, and walls and can cause fungus. Therefore, you need to start repairing as early as possible. In the article, we’ll tell you where and why the equipment can leak and how to fix it.

Main Reasons


In this article, we will concentrate only on the leakage problem. If you need information about other issues, visit this article. Excess water often appears at the top or bottom of the housing. Before looking for the problem area, disconnect the equipment from water and electricity. Here are ten types of breakdowns that can cause water leaks.

Weak Connection of Supply Channels

This situation is among the most common reasons. The supply channels are not connected tightly to each other. Check the connections to detect loose points. After that, tighten them or replace the faulty pipeline with a new one.

Housing Deformation

It appears due to irregularities during the installation. It is not the manufacturer’s fault. Most likely, the safety valve is missing or faulty. Therefore, dripping water from the boiler is noticeable immediately after installing the water heating apparatus.

During cooling, the volume of liquid decreases, and the boiler tank contracts. When all the liquid is gone, a vacuum begins inside the tank. When the safety valve is faulty, the container deforms during these processes.

Leak in Tank

If liquid flows down the line, the reservoir tank is leaking.

This issue often appears due to:

  • incorrect installation;
  • violations during connection;
  • resulting in a water hammer.

The tank is designed for a certain maximum pressure. Exceeding this pressure can lead to a water hammer, which can subsequently cause a leak.

Tank Lid Leaking

For most, this leak appears in the heating element. One of the reasons is a significant accumulation of scale. To solve the problem, you need to install a new heating element.

Leak in Heating Element


Some boilers do not have a special passage for draining water, which helps in case a tubular electric heater (TEH) leaks. Therefore, it is worth checking its availability when choosing a boiler.

Safety Valve Malfunction

A safety valve is a tap installed for safety reasons and to help when water is overheated. It releases the pressure to prevent negative consequences. First, inspect the valve to determine its condition. Repair is sometimes possible, but it is better to call a specialist.

Heating Element Problems

There are two situations of leakage from the heating element: from under the seal and a hollow place under the bolts. In the first case, tighten the nuts that secure the heating element. In the second situation, you should change the tubular electric heater.

No External Damage

First, you need to check the following conditions:

  • no problems were found when studying the boiler elements;
  • installation/connection of the water heating system was carried out without violations;
  • the magnesium rod was checked at least twice a year. If necessary, a new one was installed.

If the boiler is still leaking, returning it to the store under warranty is better. Leakage can be eliminated only when the boiler tank is made of stainless steel. It is essential to replace the magnesium rod with a new one regularly. Otherwise, the tank’s surface will deteriorate, and a new one will be needed.

Neglect of Prevention

Increased water hardness and a large volume of impurities do not have the best effect on the water heater’s operation. Therefore, from time to time, it is worth performing preventive maintenance: cleaning the device from dirt and replacing worn parts in a timely manner. It will minimize the occurrence of leaks in the water heater.

Defective or Incorrect Installation

If the device is defective, you must return it to the store before the end of the warranty period. Under these circumstances, the main thing is not to try to repair it yourself, as the store will not accept the heater.

If the cause of the leak is violations during the equipment installation, it is worth re-reading the points above and checking the boiler elements. Also, reread the installation and connection instructions to find out where the mistake was made. In some cases, you can still solve the problem.

Is Repair Possible?


In some cases, minor repairs can solve the problem. In others, you must remove the heater and buy a new one. It is advisable to do this before the warranty expires.

Here’s what to look for during your inspection:

  • Water leaks appear in the joint areas of the pipes. The cause of the malfunction is a leak in the tank. You can’t fix this. You have to replace the boiler with a new one.
  • Leakage is observed in the upper part. If the device has been properly maintained regularly, the magnesium rod has been replaced on time, but there is still a leak, and repairs will not help. You’ll have to buy a new boiler. Also, you have to replace the entire water heater if it has an old magnesium rod that has not been replaced during prolonged use. It provokes rotting of the tank (in the case of a non-enamelled inner surface).
  • The tank cap is leaking. In these circumstances, a new heater installation is necessary.
  • Leaking directly in the tank. The most unpleasant situation is that the leak comes from the bottom of the tank. The fact is that the water heater is a complete device with a single body and enameled internal walls. Once the enamel surface is damaged, it cannot be repaired.

The first place a plumber will check is the drain valve. It is located at the bottom. The valve is easily replaceable, so this situation is the simplest.


Proper maintenance is the key to a water heater’s long life. However, leaks can also appear for reasons beyond your control. Be careful and notice leaks in time to fix the problem or replace the boiler. Some issues are fatal for the heater, and the only solution is to get a new one. But you may be lucky and get away with some minor repairs.