Do-it-yourself boiler repair: possible malfunctions and instructions for their elimination

Boiler repair video

The experience of professionals and amateurs is the best adviser when doing repairs with your own hands. Perhaps useful videos will help you identify the breakdown and fix it.

An option to eliminate a boiler leak using cold welding is presented in this video:

The procedure for cleaning the boiler is clearly presented here:

This video clearly demonstrates the procedure for checking the electrical elements of the boiler using a tester:

Self-repair of the boiler comes down mainly to replacing damaged elements.Timely maintenance, proper installation and compliance with the operating rules will prevent many breakdowns and extend the life of the device.

How to repair a boiler with your own hands

Consider the main malfunctions and ways to eliminate them.

Leak in the heater

The most common problem with electric boilers is considered to be a leak. Occurs due to corrosion of the tank, when individual elements fail. Most often it is:

• Lack of grounding, which leads to electrical corrosion.
• Natural wear.
• Breakage of the safety valve.

What to do if the tank is leaking? You can not weld a leak yourself: this can lead to irreparable consequences!

Why You Shouldn't Repair Your Tank:

• The outer and inner parts are inseparable.
• In modern technology, glass enamel is used, which is easily damaged and cannot be repaired.

It happens that a leak occurs from under the flange that secures the heater. Then you need to drain all the water, remove the gasket and assess its condition. If it is damaged or worn, replace it. In order not to miscalculate with a new gasket, take the old one to the store.

No water heating

If cold water flows instead of hot water, the heater is broken. In addition to the lack of hot water, the machine can knock out RCD when connected boiler to the network. Problems with heating elements arise due to corrosion and scale.

How to understand that the scale completely covered the heating element:

• Since it precipitates, a rumble can be heard during water intake.
• There is a smell of sulfur.

To make sure that the heater is broken and does not work, diagnostics will help:

• Drain the tank.
• Open the heater cover.
• Measure the voltage at the terminals of the heating element using a tester (220-250 V).
• If everything is in order, set the multimeter to resistance measurement mode.
• Disconnect the heater from the mains.
• Disconnect the heater contacts.
• Attach the multimeter probes to them.
• When broken, the indicators will tend to infinity.
• If the part is operational, 0.68-0.37 ohms will be displayed on the screen.

Additionally, make sure that there is no current leakage to the case:

• Attach one probe to the copper pipe, the other to the heating element contact.
• If there is no leak, the display will show 1.
• If there is, the tester will give values ​​with a minus sign or, conversely, too large.

Heater cannot be repaired, needs to be replaced

It is important to choose the right part for your model, so it is better to write down the part number or take it to the store

The water temperature is above normal

If too hot water is supplied, the problem is in the thermostat or thermostat. An additional sign of a breakdown is the lack of heating when the thermostat does not turn on the heating element. To perform diagnostics and repairs, the thermostat must be dismantled.

Troubleshooting:

• Disconnect the boiler from the network.
• Drain all water.
• Remove the tank from the wall.
• Remove the lid (for vertical models, the lid is located at the bottom, for horizontal models it is on the left, for Termex models the panel screw is in the middle).
• The thermostat is marked in yellow in the picture. Disconnect its contacts and remove from the case.

Now you can check the part for serviceability. The easiest way:

Press the safety button as shown in the photo:

• Heat the copper tip with a lighter.
• If OK, the button will be disabled.

Diagnostics with a multimeter is carried out as follows:

• Set the tester knob to the maximum value.
• Measure the resistance across the contacts.
• If the multimeter does not respond, the part cannot be repaired, it is better to replace it immediately.

The boiler does not turn on for a long time, often turns off

This also indicates a problem with the heater. Due to the scale, the water can heat up for a very long time, the consumption of electricity increases, as the heat removal is disturbed. To avoid breakage, change the magnesium anode in time, which purifies water from impurities.

There are such problems:

• During operation of the appliance, the surrounding equipment also heats up. This happens when the plug is designed for more power consumption than the socket, or the contact between them is broken. It is best to call an electrician to check and replace.
• Weak water pressure. It is necessary to check whether cold water is pumped normally. Inspect the mixer, perhaps the reason is in it. If everything is in order, inspect the relief valve. Clean it from dirt and scale.
• The boiler does not turn on at all. After the repair, the device did not work? You need to check the electronics and the main board. This work is best left to a specialist.

Now you are aware of the main problems of boilers. Carry out routine inspections, install water filters, clean the heater in a timely manner, then problems will not affect you.

This is interesting: Calculation of the current transformer according to the load power of 250 kW - we describe from all sides

Causes of malfunction and repair of water heaters

Hot water pressure problems:

1. The required power for instantaneous electric water heaters is 8-10 kW. Only with such power will the pressure of hot water be strong enough. Otherwise, only a thin stream will be supplied.
2. Due to the design features of an instantaneous gas water heater, there are several reasons for a weak hot water pressure. With the formation of scale, the heat exchanger of the gas unit is clogged. A blockage in a waterworks or gas column filter leads to an automatic shutdown of the column if the pressure drops below an acceptable level.
3. There are reasons for storage electric water heaters. First you need to check the pressure of the water supply at the inlet to the storage water heater. At normal pressure, the inlet pressure is checked. If the parameters correspond to the norms, the nozzles should be checked for blockage. The meshes on the mixers or the filter at the inlet are also checked for clogging with scale.

It must be remembered that it is impossible to violate the rules for operating the water heater.

Arbitrary supply of either cold or hot water:

1. 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 large pressure of water, the outlet water temperature begins to fall, and with a decrease in pressure, it increases. In modern columns, there is an automatic decrease in the flame, but it will not be possible to completely avoid discomfort during a change in water temperature. The solution to this problem is to install a constant water pressure.
2. For a storage water heater, the gasket in the mixer, made of rubber, may be the cause. When the water heating reaches 60-90°, the gasket also heats up, which expands and covers the narrow gap. The tap with hot water is unscrewed, and boiling water begins to pour.To fix this problem with your own hands, you should replace it with a faucet with a ceramic gasket or cartridge. Also, the cause may be a break or corrosion of the hot water outlet pipe.

Repair of a malfunction in the form of a leak from the check valve:

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

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

• the device is faulty;
• incorrect grounding.

As a rule, the RCD is not intended for repair, so a replacement must be made.

Malfunctions in the form of a leak in the water heater tank:

1. If the leak occurs from the place of the body, then the reason is the depressurization of the internal tank.
2. If the leak occurs from under the plastic cover, then there can be two reasons.
3. The result of incorrect factory alignment or cleaning, or defective rubber gasket flange.
4. Leaking from other openings or at the seams. In this case, repairing the water heater is useless.

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

Scheme of the device of the water heater.

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 disadvantage of this type of water heater is a certain amount of heated water, so you should make sure how much water is heated by the water heater.

Malfunctions 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 terminals of the heating element);
• during switching on, the protection in the thermal relay starts to work (restart the circuit breaker);
• malfunction in the electrical circuit (check all components of the circuit).

Device and principle of operation

In general, we can talk about three types of devices capable of accumulating and heating water:

• electric water heaters;
• indirect heating boilers;
• gas water tanks.

All these devices have a similar design and function on the same principle. They differ only in the heat sources with which water is heated. In this case, the role of a heater can be performed by: a heating element, a coil with a coolant supplied to it (for example, a boiler), a gas burner. Structurally, all boilers have the form of a wall-mounted tank, the inner surfaces of which are covered with heat-insulating material.
. Cold water enters it through a pipe located in the lower part, and the selection of heated liquid is carried out from the upper part.

Heaters in all boilers are located in its lower part. The water in the tank is heated to the desired temperature, and then used by the owner for its intended purpose. To maintain and, if necessary, correct the required temperature, the water heater built-in thermostat. In addition, the boiler is equipped with a temperature meter, with which the user can control the degree of heating of the water, and a safety valve that prevents the unreasonable leakage of liquid.

Hot water does not flow from the boiler: why and how to fix it

The function of the storage water heater is to achieve and maintain the set water temperature. After prolonged use, situations may arise when the jet pressure becomes weak or cold water runs from the tap instead of warm. These problems appear as a result of improper maintenance of equipment, for example:

• scale deposits on the heating element;
• malfunction of the pressure reducer;
• failure of the thermostat;
• mixer contamination;
• incorrect heating mode.

Before turning on the equipment, you need to shut off the hot water supply to the riser and open the tap on the mixer. If this is not done, the air from the tank will not come out and the tank will not fill up. In addition, heated water will go to the neighbors through the riser, and cold water will flow from the boiler or stop flowing altogether.

To find out the cause of the breakdown, you should first turn on the mixer valve, disconnect the appliance from the mains, empty the tank and proceed with the inspection. You may be able to troubleshoot on your own.

scale

Hard water and high temperatures contribute to the rapid deposition of salts on the walls of the boiler and the heating coil. Scale complicates the process of heating water, and a violation of heat removal can lead to burnout of the heating element. If during the inspection it turned out that the electric heater is covered with a layer of deposits, you must perform the following steps:

• remove the protective cover;
• unscrew the bolts on which the heating element is attached;
• remove and clean the part by soaking it in a solution of citric acid;
• install the spiral in place;
• use a tester to check the contacts.

If after cleaning the heating element is operational, then the design is assembled in the reverse order.But what to do when the spiral is out of order? In this case, you will have to replace the burned-out electric heating element.

Scale on the heating element

pressure reducer

In the water supply system, pressure surges from 2.5 to 7 atmospheres occur. To protect the boiler from deformation due to such drops, a special regulator is mounted at the inlet to it. After the correct setting of this unit, the water from the accumulator and the tap flows with the same force. The pressure at the inlet to the tank and the outlet from it must be the same. If the water pressure from the device is too weak, you need to adjust the gearbox or replace it.

Low pressure in the cold water pipes can also cause insufficient water supply from the boiler. To make sure of this, you need to turn the valve on cold water. If it flows in a thin stream or is completely absent, repair work is probably underway.

pressure reducer

Thermostat

Water heating does not occur if the thermostat does not turn on the heating element. You can troubleshoot a part as follows:

• disconnect the contacts and remove the thermostat from the housing;
• press the safety button;
• heat the copper tip (the button will turn off if the element is working);
• Measure the resistance across the contacts with a multimeter.

Perhaps the overheating protection just worked, and the device was restored to working order. If the tester is silent, the thermostat is out of order, it needs to be changed.

Thermostat replacement

Mixer

Water flows out of the boiler in a thin stream - this may indicate a blockage in the mixer.You will need to unscrew the spout from the mixer body, rinse the filter mesh from debris, walk along the inner contour with a brush and assemble the structure back. A faulty hot water faucet valve can also be the cause of low water pressure. If the components are very worn out, it would be better to buy a new mixer.

Installing a filter system at the boiler inlet will help to avoid frequent replacement of consumables.

Boiler malfunctions: the most vulnerable parts of the drive

After purchasing the device, before installing it, you should carefully read the technical documentation. It will reflect the design of the device, the location of its individual parts, instructions for proper installation and operation.

In order to correctly respond to the problem and eliminate it, it is necessary to find the place of the leak and determine the cause.

Possible malfunctions may be related to the following:

• Worn protective gasket in the case
• The malfunction is caused by the operation of the heating element. Its replacement is required.
• The thermostat, temperature sensor is out of order. In high quality boilers, several redundant devices are usually installed that control each other's work.
• The leak occurred in the area of ​​connecting pipes for cold water supply and hot water outlet. Most likely, the problem arose at the installation stage, due to poor sealing of the joints.

Often, a safety valve is connected to the drive system to protect the drive. Thanks to this element, the number of breakdowns of the device is significantly reduced.

Varieties

Heating elements can differ significantly in size, power and shape.Replacement of a heating element in an electric water heater must be carried out only with the same model of the element that was installed in the device at the factory. First of all, you should find out whether the heating element of the "wet" or "dry" type is installed in the water heater.

Dry

In a heating element of a “dry” design, the probability of interaction of the element with the heated liquid is completely excluded. Such products are placed in a narrow metal cavity that physically separates the element from the water in the tank. Thanks to this design feature, the replacement of the heating element on the water heater can be carried out without removing the liquid from the boiler.

Attention! The main disadvantage of the "dry" type heating element is the higher operating temperatures. Heat transfer to water is carried out through a ceramic or air gap, which significantly reduces the effect of liquid cooling.

To reduce the likelihood of failure of the product allows the installation of a reliable thermal relay, which will work when the maximum allowable temperature is reached

Heat transfer to water is carried out through a ceramic or air gap, which significantly reduces the effect of liquid cooling. To reduce the likelihood of failure of the product allows the installation of a reliable thermal relay, which will work when the maximum allowable temperature is reached.

Wet

Wet heating elements are standard spiral parts that are installed directly into the inner tank of the boiler. Such elements, as a rule, are large in comparison with "dry" products, but their cost is much lower.

Attention! The disadvantage of a "wet" heating element is the possibility of a quick failure in a situation where the heated water contains a large amount of impurities. The resulting scale prevents the full transfer of heat, which leads to overheating of the product and its failure.

Replacing a "wet" element will require a significant amount of time, because if you need to install a new heating element, you will need to completely drain the liquid from the tank to the last liter.

Types of boiler breakdowns and their possible causes

There are many reasons for the breakdown of boilers, most of which can be fixed with your own hands.

• The boiler does not heat water. The cause may be a breakdown of the heating element or the electrical system of the device. If the water is heated for a very long time, then a large layer of salt scale has accumulated on the heating element, which must be removed. Also, scale can cause the device to turn on or off too often.
• The water is overheating. The reason may be the failure of the thermostat.

The thermostat has a special temperature sensor and automatically turns off the heating element when the water is heated to a predetermined limit.

Tank leakage or leakage from under the flange. The problem may be damage to the tank as a result of corrosion or mechanical stress. The reason is usually the lack of grounding or the natural wear of parts.

Often the cause of a leak from the tank is the wear of the rubber gasket through which the heating element flange is pressed against the body

• The plug or socket gets hot. Typically, overheating occurs due to a mismatch between the power input of the heater and the capabilities of the electrical wiring, or due to loose contacts.
• Extraneous noise in the boiler.Among the possible reasons: scale on the heating element, too narrow water pipes or a failure of the check valve that needs to be replaced.
• Error indication on the display. Devices with built-in electronics may malfunction as a result of power surges. In this case, the electronic module breaks down, which must be repaired or replaced.

An error indication is often the result of a failed electronic module, which is usually easier to replace.

• Hot water is not supplied. This means that the thermostat or heating element has failed (poorly fixed).
• Water is too hot or steam is being generated. The reason may lie in the wrong connection of the boiler or in the breakdown of the thermostat.
• Low water temperature. The temperature regime of the thermostat is incorrectly set, the heating element is installed or failed.
• Hot water is black. The reason is corrosion, which is caused by too hard water. The boiler may need to be replaced.
• The boiler is deformed (swelled). The reason is high pressure, which is not provided by the manufacturer of the device. A pressure regulator must be installed.

The pressure regulator maintains the water pressure within the limits for which the boiler is designed

• The boiler is energized. This may be due to the fact that the cable is damaged, the heating element has burst, or the electronic panel or control board has failed.
• The boiler does not turn on. The reason may be low water pressure. The instructions for each device indicate the nominal value of the pressure, which will ensure the high-quality operation of the device.The same problem can occur when contacts burn out, which eventually collapse due to a weakened fastening. Therefore, they need to be tightened regularly.
• Boiler does not turn off. The off button is melted, the temperature sensor is faulty, as a result of which the relay contacts stick and cannot turn off the heating element after the water supply stops.
• The heating elements often burn out. The reason may be a large layer of scale on the element or an incorrectly installed unit.

If a large layer of scale forms on the heating element, it starts to work with increased intensity and quickly burns out

• The appearance of air in the boiler. Air can get into the system due to a malfunction of the check valve or a leak in the gaskets.
• The boiler does not let water through or the indirect heating boiler does not see the boiler. This may indicate that the device is not properly connected.
• The geyser whistles, makes noise or blows. This behavior may be a sign of low gas pressure, insufficient draft in the chimney, dirty pilot burner wick. The whistle appears when scale is deposited in the heat exchanger or a foreign object gets there. The malfunction can also manifest itself due to a defect in the valve that modulates the burning power of the flame.
• The pipe was torn off the water heater. The cause may be incorrect connection of the device, worn fasteners and gaskets, or too much water pressure.

How does a boiler work

Distinguish between storage and flow type water heaters. The first consist of a large container in which a heating element is installed. Inside the device water enters, which is stored there at a certain temperature.

With the help of a temperature sensor connected to a thermostat, the temperature is maintained at the set level. To prevent the loss of thermal energy, the body of the storage tank is covered with a layer of insulation.

Before using the boiler, you should study its device, technical specifications and manufacturer's recommendations for operation in order to prevent breakdowns

Flow models work differently. They also have a housing and a heating element, but no water is stored inside. The device turns on at the moment when a stream of water begins to pass through its body. The liquid quickly heats up to the desired temperature. These devices are more powerful than storage models, they consume more electricity. But their dimensions are compact and installation is a bit easier.

And yet, in everyday life, the accumulative version of the water heater is more often used. Breakdowns for different types of devices are similar, and they are eliminated by approximately the same means.

To automate the operation of the water heater, use a thermostat. This element receives data on the current state using a thermal sensor. It turns on and off the heating element based on the incoming information. This helps not only to maintain the optimal temperature inside the drive, but also makes it possible to save energy.

The device also prevents dangerous overheating of the water, which can cause a serious accident.

If the boiler leaks in the area where the water pipes are connected, the installation of the device is most likely to blame, and the connections must be re-sealed

Hot water is gradually taken from the tank and replaced by cold streams from the plumbing. At this point, the heating element usually turns on.If the hot water in the boiler has not been used for a long time, it may cool down. Too low temperature also gives a signal to turn on the heating element.

Types of heaters according to the applied heating element

There are boilers with “dry” and “wet” heating elements. In the first version, the heating element is placed in a special flask, and in the second it is in direct contact with water. Both models have certain advantages. In terms of boiler repair, it is believed that it is much easier to replace a “dry” heating element than a “wet” one, since for this you just need to remove it from the flask and put a new element there.

In the case of a “wet” heating element, you will first have to completely drain the water from the tank, and only then make a replacement. Usually, “dry” heating elements are less productive than the “wet” version, therefore, not one, but two such heating elements are most often installed in the boiler.

A “dry” heating element is not as productive as a “wet” one, but it is somewhat easier to replace it, since you do not need to drain the water from the tank

Due to the peculiarities of operation, “dry” heating elements often burn out and need to be replaced, therefore models with “wet” heating elements are more popular. It is worth noting that you can also find modern boilers with very reliable “dry” heating elements of the latest generation, but the cost of such devices may be too high.

But the type of heating element does not affect the amount of scale formed during operation. But if a “wet” element has scale deposited directly on the surface, then with a “dry” heating element, deposits accumulate on a protective flask.