Among all the elements of the internal structure of the boiler, the tubular electric heater is the most susceptible to malfunctions and breakdowns. Before checking the function of this component, you need to calculate the resistance. It is calculated as the quotient of the square of the mains voltage and the power of the device indicated on the case. After that, you can measure the resistance of the heating element of the boiler using measuring equipment.
Possible malfunctions of heating elements
The device includes one or more strands of a heating element mounted in a metal tube filled with an insulating material that conducts heat well. The serviceability of heating elements is disrupted due to the fact that they bear the greatest load. In addition, a lot of scale settles on the element, which negatively affects the quality of work.
The main problems include:
- burnout of the filament;
- scale accumulations;
- burning of the 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 can get an electric shock. With the security system installed, the device will simply turn off.
In order for the heating element to last longer, it must be regularly cleaned of scale and dirt, as well as ringing with a tester when a malfunction occurs.
Multimeter Models
It is customary to find out the resistance of the heating element by means of 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 chosen to test the heater, before using it, you need to make sure that there is no violation of the integrity (including damage to the insulation coating) of the wires leading from the probes to the tested device.
Digital
When purchasing a new measuring device, it is preferable to choose models of this group. The design includes a controller, an integrated circuit and a screen that displays the measurement result. In terms of the accuracy of the readings, these products surpass analog ones. It is not determined by the zero setting or the battery discharge level - the user simply receives the 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 heating elements is a part of professional activity, it is recommended to purchase a device equipped with a signaling device. The integrity of the electrical circuit when working with it is detected by means of an audio signal.
Pointer
Such devices are directly connected to the test object. Radioelements convert the signal into an electric current that moves an arrow placed in a magnetic field. Working with the device requires strict observance of polarity. In case of an error, the pointer moves in the opposite direction until it meets the limiter, and if the signal is significant in magnitude, the multimeter may fail.If such a mistake is made when handling a digital device, it will notify the user about this with a minus sign on the display in front of the numerical value of the measured parameter.
Methods for calling a water heater
There are methods that allow you to assess the health of the device if there is no multimeter at hand when problems are detected. They give a less accurate result than working with a digital meter, but it is quite possible to assess the need to replace a part with their help.
The simplest method to check the heating element on a water heater does not require the use of any tools. However, it will be necessary to dismantle the element from the heating device. The heating element must be carefully examined. If the build-up of scale interferes with the assessment of the condition, it is dissolved by soaking the part in water with vinegar or citric acid. It takes about 6 hours to soak it in an acidified liquid.
Scale deposits cause a number of common problems with equipment - because of them, the time for heating the water increases, and the part itself, in the absence of timely cleaning, will soon burn out.
If the heating element shows scratches, any deformations or dark spots, it must definitely be replaced.
The use of an indicator screwdriver on the battery is also allowed for testing. Before testing, be sure to disconnect the equipment from the current and disconnect all conductors from the heating element. The first terminal clamp is touched with a finger, and the tip of the tool is brought to the second supply by touching the end contact. If the indicator is illuminated, the heater is not out of order.
Heating elements are tested with special control lamps. This option is suitable for professional electricians or people with sufficient experience with chains. The circuit can be assembled independently by using a 220 V incandescent light bulb. It is screwed into a cartridge to which single-core copper wires with probes screwed to them are attached. The lamp is connected to the network between the DUT and the power source. If it lights up, the node is functioning normally. To check the heating device, a network zero is applied to one of the contacts, and a phase wire with a connected lamp to the other.
Verification technology
In case of problems with the boiler, you should check the heating element on the water heater with a multimeter - this is the most reliable and accurate way to assess the condition of the part. Before starting testing, you need to separate the conductive conductors from the element.
The sequence of verification works:
- The switch of the device is placed on the range of values, where the heating element 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 heating element being called.
- If the part has not become unusable, the display will soon show a digital indicator close to that obtained in the calculations. The number "0" on the screen signals a short circuit situation. If a unit appears on the left side of the display, most likely the element's spiral has broken. Using an analog meter in such a situation shows infinity.
- Then the heating element is tested for electrical breakdown. The switch is set to the "buzzer" position. They work with one probe. They are sequentially touched to the terminals of the heater. If the multimeter is silent, the test results are satisfactory. If there was a high squeak, the heater shorted to the case.
The indicator of the thermostat is measured in a manner similar to that described in paragraphs 1-3. When colliding with a unit indicating a break, press the button of the protection unit. When the thermostat can work again, measurements continue.
If the user is not sure what range to set the resistance of the multimeter to when testing a heater or other element, tests can be performed in several different zones. After the end of each test, the position of the switch is changed. The probes should not touch the leads at this time. You cannot touch them with your hands - in this case, the resistance of the human flesh will be displayed on the board. The higher the number, the more sensitive the reaction of the device.
Removal 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 must 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 place of fastening must be hermetically sealed - it is impossible to allow liquid to get on 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.
