What is a dry heating element in a water heater?

Many, when choosing a water heater, are faced with the concept of a “dry” heating element. Such models of water heaters quickly became widespread and gained the trust of customers. They are installed in dachas and country houses where there is no central heating.

The main differences between a dry heating element and a wet one

Previously, heaters with a wet heating element were installed; the device is more like an ordinary boiler, only very large. It was a hollow tube with a spiral inside. The rest of the space was filled with quartz sand or any other material with good thermal conductivity. All this was placed in a huge tank, where it came into contact with water and heated it. Disadvantages: due to increased scale formation, energy consumption increases and heat transfer decreases.

A dry heating element works fundamentally differently: its basis is a rheostatic wire, which is placed in a ceramic insulator. It does not come into contact with water, because the product is in a closed container, which, among other things, has an anti-corrosion treatment. To improve heat conduction, an oil layer is placed between the walls.

REFERENCE! Due to the design features - in a dry heating element, the heating element is always straight; only containers with a volume of 50 liters or more are equipped with it.

Disadvantages and advantages of dry heating elements

The main advantages of this type of heater include:

1. No scale. This is a modern heating device in which the heating element is reliably protected by the walls of a closed flask and additionally treated with an anti-corrosion solution. Thanks to this, there is no contact with hard water and, accordingly, scale formation.
2. The water heats up quickly. Since the water heating element of the boiler does not have direct contact with water and is not subject to its harmful effects, the device operates without interruption, efficiently, at regular intervals.
3. Reliable thermal protection. New generation boilers are equipped with reliable thermal protection, thanks to which the device does not heat up without water inside. If this unit breaks, then only the heating element itself will fail, and not the entire water heater.
4. Easy to maintain. You can replace parts in this device yourself without resorting to expensive repairs. The heating element can be changed quickly and without much difficulty. It is advisable to undergo preventive repairs from specialists at a service center once every two to three years, which significantly saves money.
5. Boiler dimensions. Such devices have small parameters and volumes compared to heaters with a wet heating element, and are also endowed with an interesting design, which gives them an attractive appearance. They also have a higher water capacity than previous similar models.
6. Eliminates the possibility of an air lock. These models are designed in such a way that the entry of air inside is excluded, therefore, the appearance of traffic jams is also impossible. This significantly extends the service life of a heater with a dry heating element and saves money for its owner.

There are few disadvantages of such water heaters, but they still exist:

1. Uneconomical to work with. First, the device heats the metal tube, and then the water. But this minus is not always justified, since heating occurs deep inside and indirect heating of water occurs with minimal heat loss; moreover, the diameter of a dry heating element (10–12 mm) is only a couple of millimeters smaller than the diameter of a metal pipe. Based on this, we can confidently say that the air gap between the walls is too small to significantly lose heat when heated.
2. There is an opinion that the power of a heater with a dry heating element is less than that of its analogues with a wet heating element. The second representatives of the heaters actually have a coil power of 2,000 W, while devices with a dry heating element have only 1,200 W. But there are usually two dry heating elements in the heater, so the power is already 2400 W.
3. Price. It is higher than that of models with another type of heating element, but since heaters with a dry heating element have much more advantages, it can be considered completely justified.

When choosing a heating device for your home, it is better to choose a device with a dry heating element. There will be few problems with it, and it will last for many years.