How to choose a storage water heater

Hot water has become the norm in a modern house. In large cities, hot water is supplied centrally, while people in the province have either never heard of or have already forgotten. Even where there is a centralized hot water supply during the period of preventive maintenance, water can be turned off for a period of several days to several months. To create comfortable conditions and not depend on this factor, you need to install a water heater. In this article, we will consider the selection criteria and the design of a storage water heater.

Kinds

Water heaters are by source of energy:

• Gas;

• Electrical;

• On other types of fuel.

By type of heating and water movement:

Flowing. For example, a gas water heater or electric flow heater. In them, the water heats up when it flows through the heat exchanger.

Cumulative. For example, a boiler, it is a water tank. In them, a certain amount of water is heated gradually. The heating time depends on the power of the heating elements, the volume of the tank, as well as the quality of thermal insulation. Let's consider them in more detail.

Accumulative water heaters

Storage heaters are called heating tanks or boilers. They are electric and gas, as well as direct and indirect heating. Direct heating involves location heating element (TENA) inside the tank, it gives off heat directly to the water.

While the indirect heating boiler receives heat from the built-in radiator, through which the coolant flows from another heating device, for example, a boiler, solar collectors and other things.

In everyday life, electric direct-heating electric water tanks were most widely used. How are they arranged? Boilers consist of:

• The heating element (in this case, wet or dry heater).

• Tanks in which water is stored;

• Thermally insulated enclosure.

In fact, during repairs it is possible to replace only the heater, its sealing parts and water pipe seals (rubber bands).

The principle of action is as follows:

Water is collected through the inlet pipe into the storage water heater and is in it on demand. Heating occurs with the help of a heating element and is controlled by a thermostat in order to avoid boiling, due to which high steam pressure will violate the integrity of the tank. When you open the water - it enters the hot water pipeline. At the same time, hot water pressure cannot be created in the tank by itself, it is provided by the pressure of cold water at the inlet to the drive.

As a result, when you use hot water, its pressure and temperature are maintained until there is enough heated water for this. When cold water dilutes hot stocks, you need to give it time to warm up again.

What are and what to buy

Consider the main characteristics of water heaters in order to form an idea of ​​the selection criteria. Among them:

• Volume of the tank;

• Type of electric heaters;

• Power TENA;

• Capacity materials.

Volume

Accumulative water heaters, or boilers, are produced in different volumes from 10 liters to 200 and more. The greatest demand in houses and apartments are models of volumes from 80 to 100, sometimes 150 liters. While 10-20 liter models are often installed in the country, because this is enough to wash your hands or a little dishes. And 200 liter models are installed in homes by large families.

Consequently:

The larger the volume of the storage water heater - the more expensive it is.

Types of heating elements

TENY also differ. In cheap tank models, manufacturers install the so-called (WET) heating elements, and in expensive ones - (DRY) or air heating elements. What is the difference?

Heating elements are called wet because they are located directly in the water. This gives good heat dissipation, but there may be hazards associated with the risk of electric shock. The fact is that in the process of wear, the malfunction associated with the burnout of its spiral is not the only one. The heater can not only burn, but also penetrate the body. Watch -Why do heating elements burn on water heaters and washing machines and how to replace them.

In the photo you see a wet ten with a magnesium anode. It is needed in order to prolong the life of the tank and slow down its oxidation (rust). The magnesium anode is destroyed by itself. It is replaceable, if it is not replaced on time, the metal of the tank will begin to break down.

A breakdown on the body occurs when the tube gradually collapses under the influence of scale and corrosion, then the spiral can remain intact and even continue to heat the water, but electric potential will appear in the water, and when you lower your hand under a stream of hot water, you will be shocked.

To prevent this, you can install a water filter at the inlet of the tank, to reduce its stiffness, and also, if it is possible to use substances to remove scale, but this can be done if you remove the tank and pour this composition there, and then turn it on for what that time. These are time-consuming and require basic plumbing skills.

To reduce the risk of electric shock, all metal parts of the bath and tank must be grounded, and the heater itself must be connected via an RCD. On some models, the RCD is installed directly on the supply wire from the factory.

Benefits:

• low cost.

Disadvantages:

• heater service life is less than DRY;

• risk of electric shock.

In models (PRICE), dry heating elements are installed. They are not located in water, but in a flask, which in turn is installed in water. So the heating element heats the flask itself, and it gives off heat to the water.

Benefits:

• longer service life of the heater;

• security.

Disadvantages:

• cost.

There can be two TENs in a storage water heater, usually one works, and the second is switched on forcibly. This function is called differently, usually like Turbo or express.

Power and heating rate

The heating rate of water depends on the following factors:

• volume of the tank;

• power of heating elements;

• The temperature of the water from the water supply (at the entrance to the tank).

Therefore, the manufacturer's statements in the technical characteristics of the storage heater are usually approximate or average in nature.

Tank inner cover

The life of the storage tank depends on the quality and material of which the storage tank is made. With poor-quality coating and materials, it simply rusts and flows. For storage tanks, the following materials are used:

• Stainless steel. Classical material, such tanks serve 7 or more years.

• Enamel. A good but brittle coating, if damaged, the tank will begin to rot

• Glass ceramic. It is cheaper than stainless steel, but it serves less. It is not sensitive to the action of active substances - salts, alkalis and acids. The downside is that such a coating can peel off and break off when the tank hits.

Conclusion

For clarity, let's look at several models of boilers for their price and characteristics. This will help to make the right choice and make sure the influence of parameters on the cost of devices.

What conclusion can be made by looking at this table? That the time of heating the water in the boiler, although it depends on the power of the heater, but 2 models with the same power, heat the water at different times, this is due to the insulation of the case, as well as other factors that were present when the manufacturer measured this time.

The table shows the stated data. The cost of a storage water heater depends not only on materials and technical solutions, but also on the brand and additional functions, this can be seen in the comparison of the first and second models.However, the cost depends on the volume more obviously, which is confirmed by the last two models of water heaters.