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The geyser works on the basis of potentially hazardous fuel. Therefore, manufacturers supply it with a security system. In the event of a malfunction and the threat of an emergency, protection is triggered and blocks the operation of the equipment. Geyser sensors are located in different parts of the unit and monitor the operation of the system. What they are and what they are intended for, every user should know.
Varieties and principle of operation of sensors
To understand how a heater works, you need to understand its components. In the publication “Gas column device”, we described in detail what parts the unit consists of. Now let’s talk about the purpose of the sensors.
Thrust sensor
It is located in the connecting part of the chimney and the body. Its main task is to determine the presence of ventilation (draft) in the chimney.
Under normal draft, combustion products are discharged to the street through a chimney shaft. If ventilation is impaired, then reverse draft may occur, which leads to the extinguishing of the burner and the ingress of carbon monoxide into the room.
Violation of ventilation occurs for various reasons: blockage or damage to the chimney, accumulation of soot on the walls, improper installation of the shaft. A sensor is installed to detect violations. When it works, the column stops working.
Depending on the type of gas boiler or column, the combustion chamber can be open and closed. The type of sensor and the principle of its operation depend on this.
Devices with an open chamber provide an atmospheric type of burner. The flame is maintained by ventilation in the room, and the draft is maintained by the correct diameter of the chimney.
The protective sensor in such units is metal plate with outgoing contact. It reacts to temperature rise. The exhaust gases have a temperature of 120-140 degrees.
When they are normally displayed, the values do not exceed the norm. But when a malfunction occurs, gases accumulate and the temperature rises. From this, the metal on the plate expands, the contact moves away and closes the gas supply valve.
As soon as the work returns to normal, the plate returns to its original position.
In turbocharged columns closed combustion chamber. The inflow of clean air, as well as the removal of smoke, occurs through a coaxial duct using a fan. In such devices, the protection system is made in the form pneumatic relay with membrane. The device monitors the rate of exhaust gases from the fan.
Under normal flow, the membrane is in a bent state, the contacts are closed. As soon as the flow weakens, the membrane returns to its normal position and the contacts open. Then the gas valve closes.
Therefore, when the protection is triggered, do not ignore the breakdown, but try to fix it immediately.
Overheating sensor
The element is mounted on the heat exchanger tubes and monitors the water temperature. When heated above 85 degrees, it works and blocks the work. Overheating protection is also called thermal relay or thermostat. If the thermostat did not work on time, the liquid would boil in the heat exchanger. This can lead to the combustion of the radiator and damage to the speaker itself.
The heating thermostat is made on the basis of bimetallic plates or thermistors. When the value increases, its contact opens, which causes the equipment to turn off. When it fires:
- with excessive heating of water;
- in case of a malfunction of the sensor itself, a violation of the wiring;
- in case of poor contact with the installation site.
If the thermostat breaks down, an error code may appear on the display of the boiler or column.
Flame and ionization sensors
The flame or combustion sensor is a thermocouple that is heated by the flame. With constant heating, the pressure inside the element increases, so the fuel supply valve remains open. As soon as the burner goes out and the element cools down, the valve closes. It can also be called a gas sensor, as it prevents the equipment from leaking fuel during burner shutdown.
The ionization element is in contact with the burner flame. As a result of combustion, ions are produced, which are attracted to the sensor and generate current. If enough ions are fixed, the technique continues to work. If the amount decreases, the device stops functioning.
When it might work:
- in case of violation in the air-fuel supply;
- when the valve or electrode is clogged;
- when the ignition elements are dirty.
Water flow sensor
Controls the power of water flow through the column. Needed in order to disable the operation of the device when the mixer is turned off.
There is also a sensor that records the force of water pressure. He will not allow the column to turn on until the pressure force reaches the norm.
How to check and disable sensors
If you want the equipment to function normally, then you cannot turn off the protection. When the device turns off some time after heating, this already indicates that the sensors are working properly. Another thing is when an error code is displayed on the scoreboard indicating to check the part. Then the contacts are disconnected, and the protective device is called by a multimeter.
In order for the equipment and its security systems to work normally, clean the components and parts from clogging and scale. So, the fouling of the heat exchanger with scale leads to untimely operation of the thermal relay. Therefore, use reagents to clean it.
The security system for gas equipment is very important. Therefore, before buying, study the component columns, they are usually indicated in the documentation of the equipment.