Diy flow-through water heater

In detail: do-it-yourself flow-through water heater from a real master for the site my.housecope.com.

Household instantaneous water heaters are compact with a power of up to 15 kW. Before installation, permits are obtained, exceeding the load limit on the power grid leads to the operation of the protection, the apartment building will be de-energized.

The high power consumption of instantaneous water heaters is associated with the need to heat a large amount of water. 2 kW is enough for washing hands or dishes. 3.5 kW will delight you with lukewarm water for a shower. The electrical wiring of the standard "Khrushchev" is limited to 5 kW.

Let's consider some aspects of self-repair of instantaneous water heaters.

Uninsulated coils in storage water heaters pose a serious threat to human life. It is strictly forbidden to eliminate the malfunction of the heating element by simply winding the nichrome wire over the rod.

The design of an instantaneous water heater is fundamentally different from a storage water heater: there is no tank as such, the heating element is placed in a container slightly larger than the heating element itself, made of copper. The device is equipped with two degrees of protection: a thermostat that maintains the water temperature; a flow sensor that turns off the heating element when the water supply stops.

Electricity and water are no joke when it comes to human lives. It is forbidden, as they sometimes write, to place uninsulated nichrome spirals in copper tanks, which are often connected by copper pipes. This is called negligent homicide.

Finally, an argument to the readers! It is specially coated with nichrome ceramics to reduce scale formation. Metal is an unrivaled base for salt deposition. It is not accidentally supplied with an inert shell.

Video (click to play).

Electric instantaneous water heaters are arranged differently than storage ones. The tank is small, the tank is copper, so no magnesium anode is required, which additionally saves space. In an instantaneous water heater, there are at least two degrees of protection:

Traditional thermostat that controls the temperature of the water.
Flow-through sensor that protects against switching on in the absence of flow.

The two steps duplicate each other. If you turn on an empty storage water heater, the device will burn out if the thermostat probe does not contact the coil. But such a situation does not happen there, because water is taken from above.

With a low pressure, the device does not heat the water - the flow sensor does not allow the spirals to turn on.

Features of instantaneous water heaters:

Ceramic spirals are used in instantaneous water heaters. When a part of the coating peels off, the differential circuit breaker is triggered.
The use of ceramic spirals in instantaneous water heaters is economically beneficial: the efficiency is 98.5%, scale is formed in scanty amounts. Water heaters with ceramic spirals are made non-separable.
Not all models are equipped with a removable heating element. Repairing a non-removable heating element involves opening the copper sheath, which is then welded or sealed again.

Although electric instantaneous water heaters are connected through a circuit breaker, when the water supply is cut off, the fuse will not turn off the heating immediately. A piece of wire can withstand the load for several minutes, limiting the current consumption.

The devices require regular maintenance: lubrication of the internal valves to prevent gas and water leaks. Moving rods are periodically lubricated, rubber or silicone gaskets are replaced.

When carrying out work, the valves are closed.After processing, the units are washed to ensure the tightness of the joints.

When converting a water heater to a new type of gas, a trivial pressure adjustment does not give the desired result. We have to buy new components, for example, the ignition burner nozzle. Without additional adjustment, the water valve does not work correctly: a strong gas flow can depress the spring, and if there is no water supply, gas will continue to flow to the main burner.

An electric boiler is an effective solution to the problem of hot water supply for a private house. Such equipment, however, like any other, periodically breaks down.

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.

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.

To prevent it, you need to regularly, i.e. Replace the internally mounted magnesium anode annually. This element is designed specifically 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.

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.

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.

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.

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.

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 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.

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.

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.

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 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.

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 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.

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 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.

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, changes 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.

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. Image - Do-it-yourself flow-through water heater

In the first part of the article on the repair of instantaneous water heaters, the principle of operation of this household equipment was given, so that it would be easier for a novice master to understand the essence of the problems that arise.

In this continuation of the article, it will be described in more detail about the protection elements and an algorithm for troubleshooting in instantaneous water heaters will be given.

There will also be shown videos recorded by home craftsmen in the process of repairing their instantaneous water heaters.

If the flow sensor is damaged and it is jammed in the on position, then when the tap is closed, the water in this small heating zone is very overheats quicklywhich could damage the heater itself due to the increase in pressure. Also, due to the lack of cooling, the heating elements will overheat. To prevent this from happening, temperature control sensors must be present in instantaneous water heaters.

Water flow sensor for KISPEL water heater

In the model considered in the previous article, the sensors T1 and T2 are made in the form of one element, although their purpose is different. The temperature sensor T1 is set to operate when the temperature exceeds 60 ° C, it interrupts the circuit. After cooling, T1 returns to the operating position again. Exceeding the temperature in this case is possible for a number of reasons not related to a breakdown in the water heater.

Thermal sensors T1 and T2 are combined in one device, indicated as an overheating sensor

Thermal sensor T2 is set to a temperature of 90 ° C - one might say - this is the extreme line of protection. It will work in the event of a breakdown of the flow sensor and temperature sensor T1. Such a breakdown will not be eliminated by itself, therefore, this protective device after triggering is necessary enable manually after the repair of the water heater. For water heaters with a digital interface, breakdowns or incorrect sensor readings will be displayed as a highlighted error code on the display. An example of how to eliminate one of the errors is shown in the video below, which also describes the function of thermal fuses and the repair of the electronic unit of one of the models of the Termeks water heater:

Depending on the model and design of the water heater, the control system for its operation can be performed in different ways. For example, in the THERMEX STREAM model, the temperature is controlled by water flow control. Myself flow is regulated special shower or washbasin heads supplied. In this case, the protection components are a pressure switch and a thermal fuse (temperature sensor). Image - Diy flow-through water heater

Disassembled THERMEX STREAM flow heater

Accordingly, the electrical schematic diagram of this water heater differs significantly from the above wiring diagram - here the phase current sequentially passes through the pressure switch and the thermal fuse, which returns to the on position after the temperature drops. Before self-repairing the water heater, be sure to study the electrical diagram and instructions from the manufacturer.

An example of a circuit of instantaneous water heaters THERMEX STREAM

As can be seen from a comparison of two schemes from one manufacturer, the principle of control and protection in these models of water heaters is significantly different. Water heaters have a completely different design, respectively, and the scheme will be different. Below, for example, an electrical diagram of the Atmor water heater is shown.

Diagram of instantaneous water heater ATMOR, power 7 kW

Also, some models may have an electronic interface directly connected to the power relays for controlling the power supply of heating elements. This means that a breakdown in this electronic board, or a failure of the algorithm can lead to the stoppage of the water heater. Some instantaneous water heaters can have temperature control, which is achieved by switching heating elements, or using an electronic circuit.

Above, as an example, several electrical circuits of instantaneous water heaters are given, where the common components are heating elements and protective sensors. A careful study of the design and diagram of an existing faulty water heater will help you understand the principle of operation and build a troubleshooting algorithm for yourself. Will also be very helpful information from the masters, who carried out such repairs, therefore, you need to look for information on the forums and be patient, waiting for an answer to your question. You can also find helpful repair videos.

A lime-clogged shower head that has caused the water heater to malfunction can be cleaned with a cellophane bag with vinegar

For example, as mentioned above, the pressure (water flow) is often controlled by spout nozzles, which can become clogged due to sediment build-up from poor quality water. Often, the solution to the problem with an instantaneous water heater can be in cleaning the hose or nozzle, as well as in bringing the inlet pressure of the water supply to normal parameters. Indeed, if the inlet pressure is below 0.05 MPa, then the sensors will not allow the heating elements to turn on. The same can be said about the correspondence of the electrical parameters, which are also given in the table below.

Operating parameters of instantaneous water heaters Termeks Stream

If the failure of an instantaneous water heater is accompanied by the operation of an RCD that protects this power line, then the breakdown is obvious - a breakdown of the heating element to the case. In this case, a great success for the master will be a short circuit to the case in some other node - for example, a wire that has fallen off (burnt out) from the terminal.To check the heating element for breakdown, switch the multimeter to the megaohm measurement mode - the ideal resistance is infinity. Considering the conditions of using the water heater, which are critical for human health, the leakage resistance in the heating element below Megaohm can be potentially dangerous.

Even without disassembling the water heater, it is possible to carry out its preliminary diagnostics by changing the operation of the equipment, paying attention to the noise and light indication

For example, you can check the health of the flow control system by clicking on the power relays for turning on the heating element. In this case, there is often burnout of the terminals and poor contact on them, or the failure of the heating elements themselves. If you have a tester or even a homemade probe, it will not be difficult to ring the active coil of the heating element. The dialing of various conductors has been said many times on other pages of this resource. Depending on the power of the heating element, its resistance will be within units - tens of Ohms.

Calling the heating element of the water heater

After making sure that the heating element is in good working order and having checked the reliability of the contacts, you should test the relay itself - the operation of its magnetic system and a click does not guarantee the serviceability of this unit. The pads inside the relay are subject to burnout and wear. Therefore, ring the pairs of contacts of the power relay. If a lack of conductivity is detected in a closed pair of contacts, the relay must be replaced.

Instantaneous water heater power relay

Many craftsmen successfully disassemble even non-separable relay structures if they cannot find a replacement. Here is a repair advice - to find out as much as possible about the design of this relay, the sequence and the possibility of disassembling it in order to get to the switching contacts in order to be able to clean them, bend them, fix them - in a word - eliminate the problem of the missing contact.

Water flows - but does not heat up with a working relay and heating elements - which means that the liquid flow sensor itself is faulty. As mentioned above, you can check the water flow sensor with a powerful magnet, bringing it close to this component. If the suspicion is confirmed, the faulty sensor must be replaced.

Water flow sensor, often used in various models of instantaneous water heaters

The serviceability of thermal fuses and pressure sensors (pressure switches) when the pressure parameters match, you can check them with a tester. By temporarily bypassing their leads with a wire, you can make sure that the problem was in them. You should never leave the shunt to work on a permanent basis - because in this case the equipment will be deprived of protection, which can lead to very disastrous consequences - defective protective components must be replaced.

Many owners of instantaneous water heaters complain about the poor-quality assembly of their products. The most common problem is the inconsistency of the wires and terminals with the load currents flowing in them. Very often, unscrupulous manufacturers of instantaneous water heaters install cheap and low-quality components, and also save on wires and terminals.Burnt and melted terminals cause loss of contactIf, before the breakdown, during the operation of the instantaneous water heater, a characteristic smell of insulation melting was noticed, then the cause of the malfunction may well be loss of contact or even burning off a wire that is too thin. Replacing the contact terminals and wires with better and more reliable substitutes can eliminate this problem.

Diagram of an electric flow heater.

Therefore, there is a need for repairs. You may need it for various reasons.

Below are the most common breakdowns that are detected in water heaters.

Before starting repairs, you need to think about the safety of the work. Therefore, be sure to disconnect the heater from the mains. Then you need to turn off the cold water tap. Having done this, be sure to drain the hot water by turning the valve located at the bottom of the heater.

Next, you need to prepare the following set of tools, which are needed to repair the water heater:

screwdrivers;
spanners;
tester;
spare parts (depending on the type of breakdown).

Diagram of an electric water heater device.

So, one of the most common breakdowns that occurs in heaters with a very different power is the failure of the heating element. When their service life has come to an end, the following can be observed:

water does not heat up;
the indicator light is off;
water from the heater tap is poured with scale;
the power of the instantaneous water heater is not regulated in any way.

All this suggests that most likely it is necessary to change the heating element, but before starting the repair, you need to make sure that the problem is in it. After all, the boiler may have another breakdown. To do this, a device called a tester is taken, installed on a scale for measuring voltage at 225-250V, and the potential of the heating element terminals is measured. If they are normal, it means that they will not need to be changed together with the heating element. Next, the tester is installed on the resistance scale, then the terminals are removed from the heating element, and then the contact of the heating element is detected. If it is serviceable, the tester will show the value of its resistance, but if it is absent, this indicates that the heating element is out of order and will need to be changed. This is done in several stages.

At the first stage, the repair involves unscrewing the bolts that are located under the boiler cover in its lower part. Then you can unscrew the heating element itself together with the flange. This can be quite difficult to do, because during the operation of the heater, scale build-ups form on it. Therefore, you will first need to remove them, and then remove the heating element.

At the next stage, a new heating element is taken for the water heater, the power of which should be the same as that of the failed one. It is imperative to check it with a tester for performance. When you are sure that it functions and there is no marriage, you can screw the heating element with a flange in place of the old one. Then be sure to install the boiler cover and fix it with bolts.

Gas water heater diagram.

Repair of flow heaters may be required due to the fact that thermostat and thermostat malfunctions are observed. It is quite simple to find out that the breakdown is in them, because there are characteristic signs that indicate this. They are as follows:

The heating element does not turn on if there is voltage and the heating element is in good working order;
the boiler power remains minimal, even if the regulator is set at a high level;
the thermostat is triggered in the absence of water.

So, in order to find out what caused the breakdown, you need to check the parts for operability. The first step is to remove the thermostat. To do this, you need to take 2 flat screwdrivers and use them to dismantle the front panel of the water heater. Next, you need to pry the thermostat knobs with one of these tools, and then pull them towards you. After that, you will need to unscrew the screws and disconnect the power cable.Then you can easily remove the thermostat. To check it again, you will need a tester. The device must be set to measure resistance. Next, the adjusting handle is fixed at the Mach mark, and then the thermostat contacts are connected. If the tester does not show any data, then it is clear that the item being tested is defective. Therefore, all that remains is to send it to the trash can, and install a new one in its place.

If the control thermostat is working, the tester will show a certain value on the screen. Then we can say with confidence that the thermostat is faulty. It can no longer be repaired, so a new one will need to be installed in its place.

Often, the repair of an instantaneous water heater, the power of which may be different, is necessary due to the fact that it has leaked. It can arise for only one reason: the flange to which the heating element is fixed has become unusable. There is only one way out - to replace it. First you need to remove the boiler body and then unscrew the heating element. Then the flange is changed to a completely new one. Then all work is carried out in the reverse order.

Quite often, owners of instantaneous water heaters notice that there are extraneous noises during the operation of the boiler. They can often stop and then reappear. You can also observe that the capacity of the water heater has decreased, despite the fact that the thermostat remains at the same mark. All this suggests that there was a clogging of the flow-through boiler. In this case, it is necessary to do not repair, but cleaning it. This is done quite simply.

First you need to remove the cover from the water heater, and then disconnect the wires. Next, the bolts holding the heating element are unscrewed. Then the heating element is pulled out of the tank and thoroughly cleaned of scale and rust. Then they must be carefully removed from the boiler itself. This can be done using special tools that are easy to buy in the store. In just 10-15 minutes, your water heater will be clean again. After that, it remains only to thoroughly rinse it, and then install all the parts on it in reverse order.

Above are the main breakdowns that occur with an instantaneous water heater, the power of which can be completely different. Following the instructions given, you can do the repair yourself, spending a minimum of time and effort. The main thing is to do all this slowly and consistently, then there will definitely not be any problems.

At the same time, remember that if your water heater is under warranty, then in no case should you make an independent repair. After all, then you will no longer be able to get free maintenance at the service center. Therefore, it is imperative to call the master.

And finally, one more piece of advice: to avoid problems with the water heater, do not violate the rules of its operation. Do not turn on the boiler at full capacity, then it will work in a gentle mode, which will prevent its early failure.

Hot water pressure faults:

The required power for instantaneous electric water heaters is 8-10 kW. Only with this power will the pressure of hot water be strong enough. Otherwise, only a thin jet will flow.
Due to the design features for an instantaneous gas water heater, there are several reasons for a weak hot water pressure. When scale builds up, the gas unit heat exchanger becomes clogged. The blockage of the hydrosystem or the filter of the gas column leads to automatic shutdown of the column if the pressure drops below the permissible level.
There are reasons for electric storage water heaters. First you need to check the pressure of the water supply at the entrance to the storage water heater. At normal pressure, the inlet pressure is checked.If the parameters correspond to the standards, check the nozzles for clogging. The meshes on the mixers or the filter at the inlet are also checked for clogging with scale.

It must be remembered that the rules for operating the water heater must not be violated.

Arbitrary supply of either cold or hot water:

For instantaneous water heaters, the main reason is the incoming water pressure. Both electric and gas instantaneous water heaters heat the water that is in the heating circuit. With a high water pressure, the outlet water temperature begins to drop, and with a decrease in the pressure, it increases. In modern columns there is an automatic reduction of the flame, but it will not be possible to completely avoid discomfort during a change in the temperature of the water. The solution to this problem is to install a constant water pressure.
For a storage water heater, the cause may be a rubber gasket in the mixer. When the water heating reaches 60-90 °, the gasket also heats up, which expands and covers the narrow gap. The hot water tap is unscrewed, and boiling water begins to pour. To fix this problem with your own hands, you should replace it with a mixer with a ceramic gasket or cartridge. Also, the cause may be a breakage or corrosion of the hot water outlet pipe.

Repair of a malfunction in the form of a leak from a non-return valve:

check valve check (connection of a known good valve);
checking the water pressure in the system (installing a pressure gauge at the inlet of the water heater);
installation of an expanded tank.

Malfunctions of the RCD of the water heater in the form of frequent operation of the device:

the device is defective;
improper grounding.

As a rule, the RCD is not provided for repairs, so a replacement must be made.

Water heater tank leakage malfunctions:

If a leak occurs from the place of the body, then the reason is the depressurization of the internal tank.
If the leak occurs from under the plastic cover, then there can be two reasons.
Result of factory misalignment or cleaning, or defective rubber gasket flange.
Leaking from other holes or seams. In this case, repairing the water heater is useless.

Before checking the water heater for leaks, it is necessary to de-energize it and remove the bottom cover.

Water heater device diagram.

Malfunctions in the form of a small amount of hot water in the water heater:

In the case of an electric storage water heater, the main reason is incorrect connection. A significant drawback of this type of water heater is a certain volume of heated water, so you should make sure how much water is heated by the water heater.

Faults in the form of lack of water heating:

poor electrical connection of the thermostat with the heating element (it is necessary to check the connection of the thermostat with the heating element terminals);
during switching on, the protection in the thermal relay starts to work (restart the automatic protection);
electrical fault (check all circuit components).

The main advice is that you must not violate the rules for operating the water heater, so you need to study the manufacturer's instructions.

There are three metals anode rods: aluminum, magnesium and zinc. The water can be soft or hard. For soft water, a magnesium rod should be chosen. Aluminum is used for hard water, which contains more salts. It is recommended to install an aluminum rod if the previous one breaks. When installing a magnesium rod, a reaction in the water can be triggered, which increases the pressure inside the tank, resulting in component failure.

When installing an aluminum anode cord, it is not recommended to use hot water for cooking.

the gas boiler makes a loud noise;

the electric has a minimum burnout level, an unpleasant odor emanates from the boiler.

A large amount of sediment can lead to malfunction of the heating element. The reason for the long waiting time for the water jet is the presence of sediment.Water heater connection diagram.In gas boilers, sludge accumulates in the lower part where the burners are located. The ball of sediment gives off steam, which provokes the appearance of sounds that resemble a rumble. The presence of a gray odor means that there is sediment in which bacteria multiply. For disposal, an additional tube is installed. The precipitates lend themselves to dissolution. If the boiler is electric, then you need to purchase a vacuum device. In the absence of timely disposal of precipitation, problems and breakdown may arise.To clean the boiler with your own hands, you need:

Disconnect the boiler.

Shut off the water supply.

Pour out hot water and relieve excess pressure from the boiler tank. To do this, you need to open a hot water tap.

Remove the non-return valve and then drain the water. It turns out faster through the valve.

Remove the cover from the bottom of the boiler and unscrew the flange nuts.

Remove limescale deposits from the heating element and from the inside of the flange.

Replace the rod if necessary.

Check the integrity of the inner lining of the tank. Many models are coated with a layer of glass enamel, which can peel off. The scale should be inspected for blue or blue particles that stand out against the brown scale.