An electric boiler is an effective solution to the problem of hot water supply for a private house. Such equipment, however, like any other, breaks down periodically.
If serious breakdowns have to be eliminated in a service center, then any more or less experienced craftsman can perform a small repair of the water heater with his own hands.
To minimize problems with the device, you should study its design and principles of operation. Usually, in private households, not flow-through, but storage models are used, which make it possible to use electricity more efficiently. Such a device consists of a heat exchanger tank, inside which a heating element is installed - a heating element, connected to the power supply.
An important part of the device is the thermostat. This element allows you to maintain a constant water temperature inside the storage tank. The water is piped to the heat exchanger. If its temperature is too low (and this is usually the case), then the thermostat gives a signal and turns on the heating element.
The water is heated until it reaches the required temperature. After that, the thermostat works again and turns off the heating element. Hot water is taken from the tank and replaced with cold water, the heating process is repeated over and over. This is a general diagram of the device and operation of a conventional storage water heater.
The device of a storage water heater is not too complicated. The most vulnerable elements of such a device are a tank, a heating element, a thermal relay and a gasket (+)
Flow models are arranged somewhat differently. They do not heat a static volume of water, but a stream. They use more powerful heating elements that start working when the water is turned on and stop when it is turned off. To study in more detail the operation and structure of a particular model, you need to carefully familiarize yourself with the accompanying technical documentation.
The heater tank is a sturdy stainless steel container, one or two millimeters thick. No matter how resistant this material is to corrosion, nevertheless, these processes periodically arise and develop, which leads to the flow of water from the device. One of the most common causes of such breakdowns is electrical corrosion.
Flow heaters usually break down for the same reasons as storage models. Diagnostics and repair of such devices is carried out by similar methods (+)
To prevent it, you need to regularly, i.e. Replace the internally mounted magnesium anode annually. This element is specifically designed to prevent electrical corrosion. Over time, it wears out, and the owners of storage tanks lose sight of replacing this important part.
As a result, the tank, which has served well for some time, suddenly starts to leak. The incorrect state of the magnesium anode can also affect the state of the heating element. The outside of the storage tank is usually enclosed in a metal or plastic housing, and it also has a heat-insulating shell that prevents heat loss.
Regular cleaning of the insides and heating elements of the water heater from dirt and scale, as well as replacing the magnesium anode will reduce the likelihood of breakdowns
Damage to the outer shell and insulation is rare, usually due to careless handling of the device. Cracks and chips on the body of the water heater may not disrupt its operation, but this will lead to a deterioration in the properties of the heat insulator, and will negatively affect the functioning of the device as a whole.
Cold water inlet and outlet pipes - for hot water usually do not cause any problems if the installation of the heater is done correctly. Usually, a water heater is equipped with two thermostats, one of which is designed to control the water temperature, and the second monitors the state of the first device.
The electrical diagram of the household water heater device will help to correctly repair it, which usually consists in replacing damaged elements
Sometimes a third thermostat is also used, which determines the good condition of the heating element. In any case, the broken thermostat will have to be completely replaced. There are capillary, rod and electronic types of thermostats. Their design is different, but the principle of their work is the same.
The insulating gasket not only serves to seal the connection between the elements of the water heater, it is also necessary as an electrical insulator. It is recommended to replace this element regularly at every maintenance of the water heater.
The thermostat shows exactly what temperature the water inside the device is heated to. If this element breaks down, the water heater will still perform its functions, although data on the degree of heating will not be received.
Common breakdowns and repair methods
Breakdown of heating elements is a typical problem for both flowing and storage water heaters. This element works under high stress and therefore wears out quickly. If the power supply is connected, but the water in the tank does not heat up, most likely the problem has arisen with the heating element.
The heating element should be removed from the tank carefully, especially if a significant amount of scale has accumulated on its surface. Sudden movements can lead to deformation and breakage of some elements.
First, you should check if electricity is supplied to the heating element and the thermostat. In the places where the cable is connected, the presence of voltage is checked with a tester. If there is no voltage, you may need to replace the cable itself or check for a power outage throughout the house.
Regardless of the model type, each thermostat has a power button. When pressed, the device turns on, and when it is turned off, the button returns to its original position
If there is electricity and the cable is working properly, then problems have arisen with the heating element, which will have to be replaced, or with the thermostat. To figure out what exactly broke, you need to remove the thermostat and check it with a tester. Testing the health of the heating element is carried out as follows. First, the measuring scale of the device is set to the interval of 220-250 V. Then the resistance is measured at the terminals connecting the heating element to the mains.
If there is voltage, disconnect the heating element from the network and check the potential at the terminals of the heating element. Lack of response from the tester will indicate that the device is defective. If there is a reaction, you need to continue the diagnosis. First, disconnect the water heater from the power supply. Then the heating element is disconnected from the thermostat so that the contacts of the heating element remain not isolated.
Tester contacts are applied to them and the reaction is monitored. If it is, the heating element is working, if not, it needs to be replaced. In this case, it does not matter what kind of numbers the tester produces, only the presence or absence of a reaction is important. These troubleshooting methods are suitable for both storage electric water heaters and flow-through models.
To determine the health of the heating element and the thermal relay, an electric tester is used. Usually, the presence of voltage on the contacts indicates the health of the element, and its absence indicates the need for repair.
To check the serviceability of the thermostat removed from the water heater, you need to set the adjustment knob to maximum and measure at the inlet and outlet of the device. If the needle of the tester remains calm, i.e. its position does not change, which means that the thermostat is faulty and needs to be replaced.
If the arrow deviates, then you need to continue testing. Now you should set the minimum position on the thermostat and attach the test leads of the tester to the contacts. It will not be easy to continue the diagnosis alone, the probes will have to be fixed or asked someone to hold them in the correct position for a while.
After that, you need to take a lighter and heat the tip of the temperature sensor. If the thermal relay is triggered, the circuit will open, and the resistance on the tester's scale will sharply go down, then the thermal relay can also be considered serviceable. If the system does not respond to heating, then this element is damaged and needs to be completely replaced.
Occasionally, the water heater can stop working due to a blown thermal fuse as a result of dangerous overheating of the device. It is enough to correctly adjust the operation of the device for it to start working as usual.
First you need to unfasten the heating elements and thermostat fasteners (red arrows), then unscrew the screw (green arrow) and nuts (blue arrows. The thermostat is circled in yellow
If the check showed that both the heating element and the thermostat are in good order, most likely problems have arisen with the control board. It is almost impossible to repair such an element at home. It will have to be replaced with a new one, and you will have to use the help of a specialist who will help you set up the electronic equipment. Most often, you just need to contact the service center, where the required element will be selected and installed correctly.
Typically, the heating element is secured with six bolts and nuts (marked with red pointers). When reassembling, it is recommended to tighten them evenly.
A tank leak is a serious problem that cannot always be corrected on your own. In some models, either the tank or the entire heater will need to be replaced. Sometimes the leak can be sealed, but care must be taken to restore the integrity of the outer casing and the thermal insulation layer. Usually such measures are insufficient and short-lived, and soon the leak will reoccur.
If water flows from the places indicated by black indicators, it is probably necessary to replace the gasket or heating element, red indicators mark the places of leaks if the internal tank is damaged
The water heater tank most often leaks if:
- damage to the internal tank has occurred;
- the heating element has deteriorated;
- leaky gasket.
If water flows at the place where the heating element is attached, it may not be necessary to repair the tank itself. A special gasket is installed in this place, the leak can be caused by its damage. The gasket is replaced and thus the problem is solved.
A water heater tank leak usually occurs due to neglect or untimely maintenance, which also includes the replacement of the magnesium anode. Another common problem is lack of grounding. This can also lead to the development of corrosive processes and the occurrence of leaks.
If it is necessary to replace the gasket, you should choose a new one of exactly the same size and shape and made of suitable materials.
If you need to replace the gasket or heating element, it is best to first dismantle the faulty element in order to take it with you and find an exact analogue. Obtaining parts by eye can result in unnecessary costs. This replacement is relatively straightforward. But if problems arise with the tank, you will at least have to contact the service center. Immediately it is necessary to find documents for the water heater and clarify the warranty periods and service conditions.
Before starting repairs or cleaning the water heater, you must remove the protective cover, which can be located at the bottom, center or side.
Regardless of the nature of the breakdown, before starting repair work, you first need to turn off the power supply, remove the protective cover, disconnect the wires, pipes and drain the water. Wall-mounted models are usually removed from the brackets. The protective cover that hides the place for connecting the electrical wires and the fastening of the heating elements may have a different position depending on the model.
On horizontal type devices, such an element is usually located on the left, on vertical heaters - at the bottom, and on small models - in front. On some devices, you first need to unscrew the main mounting bolt located in the center. Sometimes this element is hidden under a decorative sticker.
The tubes of the temperature sensors highlighted with a blue line should be protected from any deforming effects; if they break, the entire device will have to be completely replaced
After that, you need to carefully remove the thermostat, and then remove the tubes of the temperature sensor. They must be handled with great care. If the integrity of the thermosensor tube is broken, liquid filler will leak out. As a result, the water heater will simply have to be thrown away and a new device bought.
If the thermostat of a domestic water heater becomes unusable, it will have to be completely replaced. The models of such devices are varied, it is best to choose an analogue with a similar device and characteristics.
If there are stickers on the body with the serial number indicated, they must be kept, even if it interferes with the maintenance and repair of the product. This can affect the manufacturer's fulfillment of the warranty obligations, as well as facilitate the work of the service center employees.
Correct maintenance of the appliance
The fact that there are problems in the operation of the device may indicate some changes in the mode of its operation. For instance:
- increasing the time for heating water to a predetermined temperature;
- the appearance of unusual sounds accompanying the operation of the device;
- the appearance of impurities in tap water, a change in its color, smell or taste.
If at least one of these signs is observed, the water heater should be cleaned immediately. To do this, you will have to perform the following operations:
- Disconnect the device from the power supply.
- Remove the protective cover.
- Disconnect the contacts of the electric wires.
- Shut off cold water supply.
- Remove residual water from the tank using a hose.
- Unscrew the screws holding the heating element.
- Remove the heating element and descale it.
- Clean the inside of the drive from dirt and scale particles.
- Rinse the device thoroughly.
- Check the health of the magnesium anode.
- If necessary, replace this element immediately.
- Wait until the cleaned tank is completely dry.
- Install the heating element in place.
- Reassemble the device.
- Check the tightness of all fasteners.
- Connect the water heater to the power supply.
- Check for grounding.
The heating element should be removed from the tank carefully, the bolts may be too stubborn, sometimes the heating element is difficult to remove due to too much scale layer. The heating element is cleaned by mechanical or chemical means, as is the removal of contaminants from the tank. If a large amount of scale is found inside the device, you should consider revising the operating mode of the water heater.
This phenomenon is often observed when the device has been operating at maximum power for a long time. It is recommended to set the maximum heating temperature not higher than 60 degrees in order to increase the life of the device and reduce the number of breakdowns. If the body of the heating device shocks, it is possible that the heating element is deformed and ruptured, or there is a breakdown in the control system.
Conclusions and useful video on the topic
A detailed video on diagnostics of the condition, maintenance and self-repair of domestic water heaters can be viewed here:
It is not so difficult to repair a water heater when it comes to replacing some of its elements. In the event of a serious breakdown, it would be wiser to contact a specialized service center. Correct use of the device and its timely maintenance will save you many problems and costs.