DIY electric boiler repair

This publication will not consider options for incorrect installation (you can read about this in another article) and operation (described in the instructions) of the water heater. We will only talk about those cases when boiler repairs are really required. Let's also make a reservation that the internal structure of water heaters from different manufacturers is slightly different. Accordingly, the images may not match your model, but still give an idea of ​​how to repair the boiler.

The internal structure of a water heater by the example of one of the Termeks models.

Malfunctions and their causes

An electric water heater is a relatively simple device, therefore there are only 3 types of malfunctions, however, they may have different causes.

1) The boiler does not heat the water or does it noticeably slower than before:

• Burnt out or covered with a heating element
  ;
• the thermostat is out of order;
• control board does not work.

2) The water heater is shocking:

• the heating element burst;
• defective electronic panel or control board.

2) The device is leaking:

• the heating element is faulty;
• the sealing gasket is outdated;
• corrosion of the inner tank.

Preparing for boiler repair

To identify the cause of most breakdowns, it is necessary to disconnect the water heater from the network, drain the water from it (a separate article is devoted to this) and remove it from the wall. Then unscrew and remove the cover that hides access to the heating element and other working units. For boilers located vertically, this is the bottom cover, for horizontal ones - the left one, for compact models - the front one. When repairing Termex boilers, you need to pay attention to the screw in the middle of the lid, often covered with stickers.

First, the fastons are removed from one or two heating elements and a protective thermostat, the fastening nuts and screws are unscrewed.

The red arrows mark the fastons, the green one - the screw, the blue - the nuts. The safety thermostat is marked with a yellow oval.

The protective thermostat is removed, the temperature sensors are removed from the heating element.

In no case should the temperature sensor tubes be cut! Inside them there is a special liquid that will leak out and the device will have to be completely changed. Wrapping the damaged tubing with duct tape will do nothing.

Thermal sensors are marked with a blue oval.

Now you can diagnose parts that may be faulty.

How to repair a boiler with a faulty thermostat?

The easiest way to test the safety thermostat is with a lighter. After making sure that the button is pressed, we heat the copper tip of the temperature sensor. In a working part, a protective mechanism will soon work, opening the circuit and pushing out the button. A faulty thermostat will have to be replaced - it cannot be repaired.

Green circles mark buttons in different thermostat models.

How to change or clean the heating element in a water heater?

Most often, it is the heating element that fails in these devices. In order to check its serviceability, you need a tester. On it you need to select the resistance scale (Ohm) and take measurements on the contacts of the heating element. If the device shows nothing, then the heating element is not working. Repairing the boiler in this case consists in replacing the defective part, it cannot be repaired.

We unscrew the nuts holding the heating element, remove it and replace it with a similar new one.

The heating element mounting nuts are marked with red arrows.

If the boiler began to slowly heat the water, make noise during operation, and the tester shows that everything is in order with the heating element, you need to descale the heating element. To do this, take it out of the heater and clean it from the overgrown layer. You can use special chemicals or use a regular knife. It is imperative to rinse the tank after that, as part of the scale falls into it.

Boiler repair in case of leakage

To determine the cause of the leak, you need to find out where the water is coming from. If it runs from the side seam, from under the top cover or control board, then tank corrosion has occurred. If water appears from under the bottom cover, remove it. If the leak is located near the flange, then the problem is in the gasket or heating element. If not, it is tank corrosion.

Black arrows mark the places from which water can flow out with an outdated gasket or a cracked heating element. Red ones indicate a leak in the internal tank.

There will be no problems with how to independently repair a boiler that has a leaking gasket. You just need to remove the heating element and put a new one.

A boiler with a leaking internal tank cannot be repaired. It is necessary to find documents for it and check the warranty period of the device. And either contact the service center, or you will have to buy a new water heater. Examples of successful tank welding are very rare, and the device does not last long after that.

Faulty panel or control board

Electronic or touchscreen control panels can also fail. If, after checking and replacing other parts, the boiler does not work, the problem may be in them. It is almost impossible to fix them on your own, as deep knowledge of electronics is required. There are no schemes for these boards on the Internet. New ones are available only in specialized service centers, where you have to contact.

Useful Tips

When purchasing spare parts for repairing a boiler with your own hands, it is better to take the faulty ones with you. There are many varieties of heating elements, gaskets and thermostats, so it's easy to make a mistake and buy the wrong part.

Removing the bottom cover during the repair of the Termex boiler, do not damage the silver sticker with the serial number. If it interferes, you can carefully remove and save the product in the passport. This label may be needed when calling the wizard from the service center.

Regular cleaning of the tank and heating element, the use and timely replacement of magnesium anodes and the mandatory drainage of water during a long period of boiler downtime can significantly extend its service life.

Video: DIY boiler repair