Options for replacing and choosing heating elements for a water heater

The boiler is used to organize hot water supply in the house when the centralized water supply is temporarily or permanently absent. The main working device is a heating element - a heat exchange element, a curved or straight metal tube. An electric current passes through the water-heating heating element, due to which the temperature of the tube rises, and with it the temperature of its surrounding environment.

Categories of heating elements by type of contact with liquid

Inside the heating element for heating water, a nichrome spiral is hermetically sealed, and the space between it and the outer walls is filled with quartz sand. The outer tube can be made of copper, carbon steel or stainless steel.

Open heating elements are in direct contact with water. Their main advantage is the high rate of heating the liquid and low cost, but there are also significant disadvantages:

• limited service life;
• rapid formation of limescale;
• high power consumption;
• insecurity.

Closed ones do not come into contact with water. The heating element is protected by a solid bulb. Its advantages:

• reduced likelihood of electrical short circuit;
• easy to repair and maintain;
• they serve for a long time - three times longer than open heating elements;
• consume much less electricity than open-type heating elements.

There are two important disadvantages: high price and slow heating of water.

Criterias of choice

When choosing a heating element for a boiler, it is necessary to build on the characteristics of a previously installed element.

Varieties of devices

In addition to the type of heating element by contact with liquid, you need to take into account a lot of other parameters:

• Mounting method - nut or flange. The latter is cast or stamped. Flange mounting is typical for open-type heating elements;
• The possibility of installing an anode - this element is designed to protect metal surfaces from corrosion and scale, thereby increasing the overall service life of the boiler. Gradually the anode “melts”, so you need to install a new one from time to time. If a hole for the anode is provided in the base of the heating element, then a new heater with the same hole is required.
• The shape depends on the type of storage tank. The heating element can be straight or bent. They choose a heating element similar to the previously installed heating element, taking into account not only the shape, but also the size, as well as the bending angle.
• Manufacturing material - the outer surface of the heating element can be made of copper or stainless steel. It is important that the material of the tank and the heating element coincide, otherwise, due to the potential difference, the service life of the heating element and the tank itself will be reduced. A closed-type copper heater can be located inside an enamelled steel bulb, in which case there is no need to worry about creating a galvanic pair.

Heating elements made of stainless steel are characterized by increased resistance to corrosion, and copper heating elements have a high thermal conductivity.

Features and amount of heated liquid

If the water is hard, a heating element is needed under the anode, which will partially eliminate the problem of scale and will extend the life of the boiler. The power must correspond to the volume of the heated liquid.It is recommended to purchase a part of the same power as the failed one. The heater parameters are specified in the technical data sheet of the device.

Operating conditions

The power must match the capabilities of the wiring. But this is more related to the choice of a boiler, and not a heating element, since the old element is replaced with a new one of similar power. The power of the boiler as a whole also affects the heating rate of a given volume of water. If the heating element is low-power, for example, 1000 W, and the capacity is 80 or even 100 liters, the water will heat up to the maximum temperature for a very long time, several hours, so you need to turn on the boiler in advance. This capacity is optimal for small boilers, up to a maximum of 50 liters.

If a large hot water consumption is planned, it is recommended to buy a model with two heating elements. They heat the water faster. In economy mode, one element will work, and the second will be connected thanks to the thermostat when it is necessary to heat a new portion of cold water.

Types of heating elements according to the principle of operation

The features of open and closed heating elements are clear from the name. The former are not protected from water, the latter are closed by a flask. In other words, they are called wet and dry. The principle of their work should be considered in more detail.

Wet

Wet-type heating elements are tubular, in direct contact with water and heat the water with their surface. Their service life depends on the quality of the water, its hardness, and the percentage of salts. Due to the influence of these factors, the metal corrodes, and limescale forms on the surface. By installing a magnesium anode, the process can be slowed down, since the element attracts salts. Glassy enamel is also used to protect the water heating pipes.

Dry

Dry heating element is a heater, which is placed in a flask filled with a second layer of ceramic filling (the first layer fills the space between the nichrome spiral and the tube in which it is placed). The waterproof shell is made of magnesium silicate or steatite. Steatite heats up quickly and cools slowly, has increased strength and high thermal stability. There are more advantages of using a dry heating element in a water heater than disadvantages, and in particular, to replace such a heating element, you do not need to drain water from the boiler.

The heating element of a dry heating element does not come into direct contact with water, but due to an increase in the thickness of the element, its thermal conductivity decreases, and the water heats up more slowly at the same power. At the same time, the heat transfer area is increased, which makes it possible to somewhat compensate for this disadvantage.

How to properly replace the heating element in the boiler

The need to replace the heating element arises when it malfunctions. When it stops heating the water, an electrical safety device is triggered. The average service life is 4 years. Then it fails due to the increased hardness of the water. This event can be postponed if the boiler is serviced annually: to clean the heating element and magnesium anode from scale. This operation will increase the duration of operation and improve the quality of water, the rate of its heating. Before purchasing a new element, it is worth checking the condition of the old heating element using a test lamp or a multimeter. In the first case, a simple electrical circuit is assembled, including a lamp and a heater. If the light is on, it's not the problem. In the second case, the resistance is measured with a special device. A zero value indicates a heater malfunction.

The designs of different models of boilers have minor differences, but the very principle of replacing the heating element in a water heater is the same for all types of devices.

To begin with, turn off the water supply, and the remaining liquid is drained from the boiler.The water heater must be de-energized by pulling out the plug from the outlet. At the bottom of the boiler there is a cover that is fixed with screws. They need to be unscrewed with a screwdriver, and the cover will come off. For safety reasons, before starting to replace the heating element in the boiler, you need to check the presence of voltage at the terminals, for example, using an indicator screwdriver. Then the wires are disconnected and the nuts holding the heater in place are unscrewed. They replace the heating element on the water heater, having previously checked that the contacts are dry. If an anode is installed in the boiler, replace it as well. Check the seal for leaks and screw the cover into place. After these manipulations, it is necessary to fill the boiler with cold water and bleed air from it by opening a hot water tap. Only now can it be included in the network.

Popular manufacturers

You should choose a heating element from a trusted manufacturer. This is not an element to be economized on. The best firms include:

• Thermex (Thermex). Has been producing boilers for almost 50 years. This manufacturer makes heating elements from copper and stainless steel. They are reliably protected, therefore they have a long service life. On the market, Termex has established itself as a manufacturer of boilers of the largest volume, therefore, the range includes powerful electric heaters.
• Ariston. The heating elements from the Italian manufacturer are made of an alloy containing copper and equipped with a chromium-nickel tube. The flange is made of brass, which increases the heat dissipation. They are well protected from limescale, easy to install. And at the same time they are relatively inexpensive. Ariston offers water heating heating elements with thread and thermostat from 1.2 to 4.5 kW.
• Electrolux. You can pick up a heating element from this manufacturer for almost any heater model. At the same time, they are guaranteed to last a long time, since they are especially resistant to scale and are not demanding on water quality. A water heater with heating elements from Electrolux does not require frequent maintenance. In some devices from this manufacturer, two closed heating heating elements are installed, so it is possible to increase the rate of heating the liquid.
• Timberk. Another manufacturer that offers its products at an affordable price. The assortment includes heating elements designed for boilers of 80 liters or more. They are well protected against corrosion and other destructive factors.
• The firm Atlantic is also known. It produces a wide range of high-quality and reliable heating elements for boilers, including copper water heating elements, dry steatite and others, suitable for vertical and horizontal installation.

Each manufacturer produces electric heaters designed for installation in boilers of their own production. However, you can also find universal heating heating elements. They are less popular due to their questionable quality, but their use is possible.

Without a heating element, the operation of the boiler is impossible. This is the most important element, which is selected taking into account the volume of the water heater, the characteristics of water consumption. Be sure to take into account which heating element was installed in the boiler earlier. It is advisable to choose exactly the same or as close as possible in characteristics. You can replace the defective part yourself.