A tubular electric heater can be used both for heating (as part of a radiator) and for providing a home with hot water. The first thing to do when putting it into operation is to protect the system from a possible breakdown of the electric heater, as well as create conditions for its autonomous operation. A popular method for solving this problem is to use a thermostat for heating elements. This small device, also called a thermostat, will help you solve many problems.
Composition of water heating equipment
The simplest water heating or heating element should consist of at least three elements - a water tank, a heating element - a heating element, and a thermostat. The tubular heater can be submersible and dry. In the first case, it is made of stainless steel and placed inside the tank. Water is heated by direct contact of water with a heating element.
Dryheating elements are made of ceramics, located outside the water tank. Heating of the coolant occurs due to the transfer of thermal energy through the tank wall. Such elements are easy to replace in case of failure.
The thermostat for the heating element is designed to control and maintain the set temperature of the coolant, as well as for emergency shutdown of the tubular electric heater from the network if the boiling process begins (as a rule, this happens when the heating element breaks down).
There are several types of thermostats, each of which is suitable for use with a certain type of tubular electric heating element.
Basic operating principles
Regardless of design and execution, all thermostats operate according to the same scheme. For operation, the thermostat must be built into the tank, and also connected to the heating element. The whole temperature control process can be divided into 4 steps:
- The toggle switch sets the required temperature range of the coolant.
- The thermostat for a heating element with a programmed mode measures the degree of water heating and gives a command to turn on the device.
- When the water temperature reaches the set upper heating limit, the thermostat opens the electrical circuit and turns off the heating element.
- After the water cools down, the whole process is repeated.
It is worth noting that no matter what temperature range you set, the thermostat will turn off the heating element if the water begins to boil. This is necessary to prevent breakage.heating equipment.
During boiling, the process of intense vaporization begins. As the amount of steam increases, so does the pressure inside the tank. As soon as the pressure value exceeds the critical level, the tank will explode. The thermostat for the heating element does not allow this to happen, opening the electrical circuit in advance.
Types of thermostats
The principle of operation of the device always remains the same. Only the principle of determining the temperature of the coolant depends on the type of thermostat. According to this, all thermostats are usually divided into rod, capillary and electronic.
Rod devices, as the name implies, have the shape of a rod with a length of 25 to 50 cm. The principle of determining the temperature is based on the difference in the coefficient of specific thermal expansion of the two metals. The rod thermostat is installed outside the water tank in a special tube.
The capillary temperature controller of a heating element for heating water is a hollow tube, inside of which a special liquid is “sharpened”. As the temperature rises, it expands, begins to put pressure on the walls and act on the membrane, which opens the circuit. When cooling, the reverse process occurs.
The work of electronic thermostats is based on the ability of materials to change their ohmic resistance along with temperature changes. As a result, the voltage in the device increases or decreases, which is registered by special sensors and turned off eitherinclude heater. Electronic instruments are the most complex and expensive, but also the most accurate.
Heaters with built-in thermostats
The heating element separately from the thermostat is rarely used in practice. As a rule, such a solution has proven itself only in water-heating boilers. Heating elements for heating radiators with a thermostat are much more common.
In such "combined" devices, the thermostat is located in a separate tube, and it is easy to replace it if it breaks. When choosing devices in this category, you need to pay attention to the following points:
- Case material. It can be represented by "stainless steel" (the cheapest and most common devices), as well as copper. Copper appliances last longer, but also cost an order of magnitude more.
- Power. For a home electrical network, it is dangerous to choose devices more powerful than 2.5 kW - there is a risk of overload and short circuit. When using more powerful heating elements, run a separate power cable.
When choosing a heating element with a thermostat for a battery, you should not focus on expensive models. Practice shows that the durability of devices does not depend on the price. The service life is determined by the hardness of the water, the loads and the stability of the electrical network.
Fields of application for heating elements with a thermostat
The scope of the heating element with a built-in temperature controller is rather narrow, due to high energy consumption and short service life. They are most widespread inwater heating equipment. This "water tank" is installed in the shower room or in the kitchen and serves as the main or backup source of hot water.
Very rarely tubular electric heaters are used for space heating. In this case, the element is installed directly into the radiator through a special fitting. The main advantages of installing a heating element with a thermostat in a heating battery are speed. With such a simple solution, you can very quickly provide a house with a backup source of heat.
Features of heating elements for cast iron batteries
Tubular electric heaters for ordinary and cast-iron radiators are almost the same. The only exception is the plug material - it must be made of cast iron or an equally heat-resistant material.
In addition, the shape of the outer part of the housing where the thermostat is installed may also differ. In this case, the length of the heating element should be 5-10 cm shorter than the length of the radiator. Otherwise, water circulation and heating cannot be achieved. Therefore, before buying, make sure that the heating element with a thermostat for cast iron batteries is designed.
Temperature controllers on the market
Thermostats for heating elements can be called consumables. That is why it often goes separately from the heating element. To replace it, you just need to pick up a similar device on the market. To do this, find out:
- Dimensions, type and method of fixing in the tank of the releasedinstrument failure.
- The maximum current that the new thermostat will have to handle.
The best option would be to buy the same device that has fallen into disrepair. This can be done by contacting the store with a faulty thermostat. In most cases, the sellers themselves will select the necessary device for you.
