Among all the elements of the internal structure of the boiler, a tubular electric heater is most susceptible to malfunctions and breakdowns. Before checking the functioning of this component, it is necessary to calculate the resistance. It is calculated as the quotient of the square of the mains voltage and the power indicated on the housing of the device. After that, it is possible to measure the resistance of the heater in the boiler using measuring equipment.
Possible malfunctions of the heater
The device includes one or more strands of a heating element mounted in a metal tube filled with insulating material that conducts heat well. The serviceability of the heating elements is violated for the reason that they bear the greatest load. In addition, a lot of scale deposits on the element, which negatively affects the quality of work.
Key issues include:
- burnout of the filament;
- accumulations of scale;
- burning wiring on the case.
The latter phenomenon is less common than the first two, but it is the most dangerous: if the heater is not equipped with a residual current device, the user may be shocked. With a security system installed, the device will simply turn off.
In order for the heater to last longer, it must be regularly cleaned of scale and impurities, as well as ringing with the tester in case of a malfunction.
Multimeter Models
It is customary to recognize the resistance of a heater using multimeters. You can find digital and analog devices. They are used for similar purposes, but the principle of operation is different. Regardless of the option selected for testing the heater, before using it, you need to make sure that there are no integrity violations (including damage to the insulation coating) of the wires leading from the probes to the device under test.
Digital
When acquiring a new measuring device, it is preferable to choose the models of this group. The design includes a controller, an integrated circuit and a screen on which the measurement result is displayed. In terms of accuracy, these products are superior to analog ones. It is not determined by setting the zero value or the level of battery discharge - the user simply receives numerical data. Some products are equipped with additional functionality - with their help you can find out where the wiring is hidden in the thickness of the wall, test radio components. If testing of heating elements is part of a professional activity, it is recommended to purchase a device equipped with an alarm device. The integrity of the electrical circuit when working with it is detected by means of an audio signal.
Arrow keys
Such devices are directly connected to the test object. Radio elements turn the signal into an electric current that moves the index arrow placed in the magnetic field. Operation with the device requires strict polarity. If an error occurs, the pointer moves in the opposite direction until it encounters the limiter, and if the signal value is significant in magnitude, the multimeter may fail. If such a mistake is made when handling a digital device, it will notify the user of this with a minus sign on the display before the numerical value of the measured parameter.
Water heater ringing methods
There are methods to assess the health of the device if, if a malfunction is detected, there is no multimeter at hand. They give a less accurate result than working with a digital meter, but to assess the need to replace parts with their help is quite possible.
The simplest method to check the heater in a water heater does not require the use of any tools. However, it will be necessary to dismantle the element from the heater. TEN needs to be carefully examined. If the build-up scale is interfering with the condition assessment, it is dissolved by soaking the part in water with vinegar or citric acid. Soak it in acidified liquid for about 6 hours.
Scale deposits cause a number of common problems with the equipment - because of them, the heating time of the water increases, and the part itself, in the absence of timely cleaning, soon burns out.
If scratches, any deformations or dark spots are found on the heater, it should definitely be replaced.
The use of an indicator screwdriver on the battery is also allowed for inspection. Before testing, be sure to disconnect the equipment from the current and disconnect all conductors from the heater. The first terminal clamp is touched with a finger, and the tip of the tool is brought to the second supply terminal by touching the end contact. If the indicator lights up, the heater has not failed.
TENs are tested with special control lights. This option is suitable for professional electricians or people with sufficient experience in handling circuits. The circuit can be assembled independently by using an incandescent bulb of 220 V. It is screwed into a cartridge, to which copper single-core wires are attached with probes bolted to them. The lamp is connected to the network between the device under test and the power source. If it lights up, the unit is functioning normally. To test the heating device, a network zero is supplied to one of the contacts, and to the other, a phase wire with a connected lamp.
Verification technology
If there is a problem with the boiler, you should check the heater on the water heater with a multimeter - this is the most reliable and accurate way to assess the condition of the part. Before you start testing, you need to separate the conductive conductors from the element.
Testing sequence:
- The device switch is placed on a range of values where the TEN indicator should fall. It can be calculated by knowing the power consumption of the device and its operating voltage. The larger the first parameter, the lower the resistance value.
- The probes of the measuring device are placed on the contacts of the called TEN.
- If the part has not fallen into disrepair, the display will soon display a digital indicator close to that obtained in the calculations. The number "0" on the screen indicates a short circuit situation. If a unit appears on the left side of the display, it is likely that the element’s spiral has broken. Using an analog meter in this situation shows infinity.
- Then the heater is tested for electrical breakdown. The switch is set to buzzer type. Work with one probe. They are successively touched to the terminals of the heater. If the multimeter does not make any sounds, the test results are satisfactory. If there was a high squeak, a heater shorted to the housing.
The temperature control indicator is measured in a manner similar to that described in paragraphs 1-3. In a collision with a unit indicating a break, press the button of the protection unit. When the thermostat can work again, measurements continue.
If the user does not have confidence in what range to put the resistance of the multimeter when testing a heater or other element, it is possible to conduct tests in several different zones. After each test, the switch position is changed.The probes should not touch the terminals at this time. You can not touch them with your hands - in this case, the display will show the resistance of the human flesh. The larger the number, the more sensitive the response of the device.
Dismantling and installation of the heating element
If the heater is worth replacing, you need to buy a new part and install it in place of the old one. The new element should be identical to the previous one in form and power indicator, preferably the same company. Before installation, it is tested for breakdown on the case. The mounting location must be hermetically sealed - do not allow liquid to enter the clamps and contacts.
The described methods are relevant for testing heating elements in a variety of household appliances - boilers, electric kettles, washing units, irons.
