Boiler: what it consists of and how it works

Boiler - a device for heating water from the mains. He is indispensable in non-gasified homes. Water heaters have an uncomplicated device: the body, tank, the system of pipes and valves, electric tube heater. Let's take a closer look at the composition of boilers, and how they work. This will help to know some of the features of the design of water heaters, which will help to choose the right equipment.

Boiler structure

Electric storage water heater consists of such parts:

• The outer casing is made of metal and covered with enamel.
• A layer of expanded polystyrene foam for thermal insulation. The material does not deteriorate from temperature fluctuations. It retains its properties throughout the life of the water heater.
• The internal water tank is made of stainless steel. Boiler tanks are also made of black steel coated with enamel or glass ceramic.
• Two tubes. One to deliver cold water to the tank. The other to deliver hot water from the tank.
• A tube to install a thermostat or temperature sensor.
• Electric tube heater for the boiler.
• A magnesium anode protects against salt deposits and prevents the metal from corroding.
• Some boilers have a recirculation spigot, in which the hot water moves in a closed system. It can be connected to the metal curved coil in the bathroom.

The most significant difference in the design of water heaters is the electric tube heater device. The heating element comes in these types:

• Electric tube heater, which is placed in the water is a spiral wire in ceramic insulation in a metal tube. The space in it is filled with sand or magnesium oxide. Over time, scaling builds up on the surface of the insulating tube. This reduces the thermal conductivity and leads to overheating of the electric tube heater. Therefore it is necessary to descale the electric tube heater regularly.
• The other type of electric tube heater is installed in the water heater body in a sealed bulb. On its surface also scale is formed, but it does not affect the operation of the heating element.
• Indirect heater differs in that it does not use an electric tube heater, and the heat exchanger in the form of a coil. It circulates hot water from the boiler.

In boilers also install ceramic heating elements. The advantage of this material is that no scale is formed on it. Such parts of the boiler serve for a very long time.

Boilers can be flow-through. Their peculiarity is that there is no tank in the design. Water passes through the system by transit. The heating element increases the temperature of the flowing water. The disadvantage is that it is impossible to keep a supply of hot water in case of power outages. The advantage of flow-through boilers is their compactness. They quickly heat water.

How a boiler works

Electric tube heater heats water. It rises to the top of the tank and from there through a pipe flows to the faucet. The volume of liquid that is gone is immediately compensated with cold water. The cycle is repeated continuously. It is important to keep in mind that if the water flow rate is high, the exchange of heated and cold liquid will be fast. At the output its temperature will drop because it will not have time to heat up. If you are going to use hot water intensively, choose a boiler with a large tank.

When the water in the boiler is heated to a predetermined temperature, a sensor or thermostat fixes it. The power contact of the heating element opens. The water heating stops. When the temperature in the tank drops below the set level, the thermostat detects this and the electric tube heater power circuit closes. The water heats up.