Home Article The boiler does not warm the water in the tap

The boiler does not warm the water in the tap

Reasons why boilers do not warm hot water

The easiest and cheapest way to organize hot water supply is a double.circuit boiler, which simultaneously ensures the heating of the room and heat water. Popular designs are products under the brand “Ariston”, Bax “. These models attract customers and are included in the TOP sales. Despite the simplicity of the mechanism and a large number of advantages, such equipment often fails. The boiler does not warm water for many reasons. Sometimes, to restore the performance of the device, there is enough small maintenance, and in some cases expensive major overhaul is required.

The common breakdowns of boilers include:

  • leakage of the coolant;
  • Hydrodar;
  • After turning on the burner, the lock is triggered;
  • The burner does not turn on;
  • fuel burns unevenly, wave.shaped;
  • soot is formed;
  • decrease in performance;
  • During the operation of the burner, ignition is turned on;
  • a soot is formed on the walls of the chimney, the combustion chambers.

To eliminate the malfunction, it is initially necessary to establish the cause of the problem.

Built.in pump malfunction

An important detail in the heating system is a circulation pump. The quality of heating and the functioning of hot water supply depends on its uninterrupted work. There are several signs and causes of breakdowns:

boiler, does, warm, water
  • The unit makes uncharacteristic sounds. This is due to the oxidation of the shaft, entering the design of an extraneous object, with power problems, air in pipes, dry progress of the mechanism, and the appearance of cavitation.
  • After turning on the boiler, the pump does not start. There may be no power supply, the fuse worked.
  • After a short period of time after turning on, the structure is turned off: Lime plaque in a glass of stator.
  • Hot water does not include in a dual.circuit boiler.

Also, the reasons for the poor operation of the circulation pump are poor pressure in the system, the wear of the bearing, which causes additional vibrations in the highway, low pressure.

To eliminate malfunctions, you need to check the presence of electricity, clean the pipes and other elements, replace the failed parts, eliminate extraneous objects from the system.

The heat exchanger clogged

Heated gases are transported through the channels, which are called the heat exchanger in the complex. Features of the design are that the walls of the artery simultaneously perform the function of the partitions of the water circuit, along which the coolant is constantly moving, heating the metal surface. The combustion process is associated with the intensive discharge of smoke gases partially consisting of soot, resins that create a raid inside the boiler, on a chimney. Therefore, the manufacturer recommends regularly cleaning equipment at least 1 time in 30 days and during the preparation of the device for the heating season.

When setting up soot on the surfaces, the productivity of the mechanism decreases, fuel consumption increases, the risk of expensive breakdowns and internal ignition in the area of ​​pollution increases.

How the equipment works?

First of all, it is necessary to understand the basic principles of gas equipment. An ordinary double.circuit boiler designed for heating and hot water supply of the house consists of three main blocks.

The first. gas. is responsible for ignition and subsequent combustion of fuel. The second. water. designed to supply water, heating and injection of pressure in pipelines. The third node is used to remove combustion products outward.

Turning the boiler starts a chain of sequential operations:

Water circulates the heat exchanger and heats up;

After reaching the set temperature, the gas supply stops, and the equipment is turned off.

When the air temperature in the room becomes below a certain level, sensors are triggered. The boiler equipment is launched, and the described cycle is repeated.

DHW does not heat up. the causes and elimination of the malfunction.

The most common reason why the DHW does not heat up is a strong scale formation inside the heat exchanger. The scale not only narrows the duct of the water in the heat exchanger, it significantly reduces the temperature of the water.

The reason for this. The thermal conductivity of scale salts is many times less than the thermal conductivity of the metal from which the heat exchanger is made. The unit does not give (does not supply) hot water or it runs weakly if a piece of plaque has broken off and blocked the duct of the liquid.

Hot water does not enter the crane when the duct sensor does not work. It is a fan that works when water flows through it. In this case, the signal from it comes to the control board, it gives a command to heat water. The sensor can clog, it can be cleaned without dismantling it.

The sensor is a cylinder located near the circulation pump. For cleaning, just open and close the tap in front of the device. If this procedure did not give a result, you will have to dismantle it, clean and put it in its former place. If the sensor is non.working, you have to change it.

If a three.way valve is faulty, the unit does not produce hot water. The purpose of the three.way valve is to block the heating system when the tap with hot water opens. When the valve does not switch, the boiler continues to heat water for heating.

The cause of the valve malfunction may be elementary clogging, for example, a piece of rust. If the problem is more serious, replace the valve with a new. In addition, one of the simple reasons why hot water does not run from the tap can be clogging of gas hoses or a gas filter.

Three.way valve in context

On heating it will not be so imperceptible, but at the temperature of the water from the tap, it will be more significant. Clean the hose and filters. Some of the above points may be the causes of heating and hot water problems in wood, electric and solid fuel (TT) boilers, provided that similar structural parts.

Three-way valve

A three.way valve is installed in boilers with two heat exchangers. When the signal from the duct sensor arrives, the electronics gives the signal to the valve and the heated water from the first heat exchanger is sent to the second heat exchanger, where the heat is transmitted by passing water water. If, for example, the actual switch does not occur (the valve is faulty), then the coolant will continue to circulate in the heating circuit and heat transfer to the hot water circuit will not occur.

If, for example, the valve overlaps the heating circuit only partially due to the malfunction, then there will be problems with insufficient heating of hot water, since part of the heat will go to the heating system.

What to do if the Vailant boiler does not heat hot water

I found this method. At the entrance to the boiler, I have a magnetic converter that should remove water hardness, but it does not remove it, in my opinion it is a fiction. But it is good for me that it is installed right at the entrance to the boiler. The photo in the bottom is visible.

On it is a nut of an American unscrewing which you can easily fall asleep into the pipe pipe with citric acid pipe.

But for this you need to block water. I have a collector next to the boiler. He is in the photo below.

Now on it all the ducts are open and in one easy movement, I block the supply of water to the boiler.

All water is blocked, now you can unscrew the American on a magnetic filter. And do not forget, to come up with something, from current water from the boiler, it is not much but it is. I wiped my rag.

Then in the inside of the pipe I fall asleep of citric acid.

What to look for if you get central heating, but no hot water.

boiler, does, warm, water

I tighten the American back and open the tap water tap to the boiler.

Now it is important to understand when the acid enters the heat exchanger. Since my water tap is a meter from the boiler, I determine whether the acid has come to the heat exchanger to taste

I just open the crane with short jerks and taste, as “sour” has gone, the whole system from the magnetic filter to the tap is filled with citric acid.

Next, you need to block the crane so that your home does not pour all the acid ahead of time.

I refuel the system at night and until the morning it is worth acidified. In the morning I open the water supply crane into the boiler and drain all the acid. The water will hiss, not Pugaites.

The question may arise, not the heat exchanger acid? I swap on the forum of chemists and came to the conclusion that organic acid (citric relate to it) is harmless to copper.

I use this method as it is impossible. If you do not like how the boiler heats water or the pressure of hot water has become weak, I take and process the heat exchanger with citric acid.

If you have an eyeliner to a polypropylene boiler, and there is no way to fall asleep, then think that a similar one will not take much time.

Design features of the Baxi gas boiler (Baxi), Navien, Ariston

In any case, familiarization with the technique of this class and the features of modern models will come in handy. This knowledge will help you choose the right equipment, do not make mistakes during operation.

In household boilers, Baxi (Baxi), Navien and Ariston for heating water are burned with gas, diesel and solid fuel, and electric heating elements are used. For more complete use of the potential of energy resources, heat exchangers improve. They make long ducts of complex shape in order to ensure prolonged location of the liquid in the working area.

The current trend is compactness. Manufacturers offer gas boilers with square cases of a relatively small thickness. Some models in their aesthetic characteristics deserve quite in a prominent place.

The following feature is the introduction of automated control systems. They control the combustion process, change the operating modes taking into account the readings of temperature sensors on the street and in separate rooms. When overheating, the technique turns off without intervention by the user.

It is necessary to carefully consider the situations when the gas boiler of the Baxi does not warm the water. This happens, for example, when the supply of energy resources is stopped. It is not difficult to make an appropriate verification even without special professional training.

Circulation pumps, valves, other typical nodes and assemblies rarely fail. Their designs are designed for many years of operation without compulsory maintenance. There are no moving details in electronic circuits at all. Their breakdowns occur due to marriage. Subject to the rules established by the manufacturer, the resource of modern gas boilers of heating is more than 10 years.

Damage to the electric part of the equipment can throw voltage throws in the power supply network. To exclude such influences, an external stabilizer is installed. Checking the grounding system is useful. This set of preventive measures for this group of problems is exhausted.

It is much more difficult to protect against the most common cause of damage to gas boilers. Nakipi. It is she who will be studied in detail in this article. When heating calcium and magnesium salts, they are converted into a solid state. It is these impurities that clog the narrow technological holes in the heat exchangers. They also form a porous structure on the surface of electrical heating elements. With a significant violation of the normal removal of the heat of their body, their body is damaged.

To prevent the formation of scale and lime inside the boiler, it is advisable to install not chemical filters (water converters), magnetic and electromagnetic, which will provide a long “life” of your boiler and uninterrupted supply of hot water, and also protect the heating circuit.

Such filters (scrap converters) like aquashchit or MWS do not use chemical reagents and interchangeable cartridges in their work. Once by installing such a device in front of the boiler, you will forget about the problem of scale for many years!

Solving the problem using a half.accommodation filter

The main disadvantage of typical membranes of the reverse osmosis is limited performance. This problem was solved by manufacturers of sexual accommodation filters. Modern products of the corresponding category are capable of processing from 1000 to 8000 liters of liquid per hour with the subtlety of cleaning from 0.01 μm.

Such a filter delays the smallest crystals of hardness salts, organic impurities, rust, other pollution. Equipping equipment can be performed manually without disassembly by connecting a separate pipe to the drainage system. For automation of this procedure, electromagnetic valves are installed with control at the signal of the timer or consumption meter. Previously, you should put the trunk filter of rough cleaning, which will prevent rapid clogging of the main working unit.

Weak duct of water

If your boiler has stopped warming the water and you see a weak pressure from the mixer, then first check whether it sees the duct or not. Simply put, there should be some kind of indication on your boiler, on the scoreboard shows or a light bulb near the crane icon burns.

When the mixer is opened on hot water, an indication appears, but there is no hot water, then consider that you are lucky. This malfunction is treated in an hour with a little effort. I will tell about it below.

If there is no indication when opening the tap of hot water, then scroll down the page down and look for the item: the boiler malfunctions.

Hot water has gone, but it heats up for a long time and heats up to only 40 or 50 degrees?

In 90% of cases, this is clogged with a heat exchanger. Read and watch the video how to clean the heat exchanger.

If you have an indirect heating boiler, then rinse and clean it, replace the anode.

With a weak duct, I always start with checking and replacing aerators with mixers.

Combi boiler hot water issues. Repaired and principals explained.


The aerator is a device on a foul of the mixer, which adds air bubbles to the stream of water. Therefore, there are practically no splashes from mixers with aerator.

The device is quite simple. housing, plastic and steel mesh. Made a photo instruction on how to clean the aerator from a lime plaque. Listen the gallery to the side.

If you have hard water, then small holes in aerators are contaminated with a lime coating and preventing a water duct. First of all, remove the aerators and clean them with citric or acetic acid.

If it is possible to buy new ones, then it is better to change them. I buy them for 50 in household stores.

Replaced the aerator, and the boiler does not warm the water? You have to disassemble it.

To repair a gas boiler, I recommend calling a service specialist and not disassemble the boiler with your own hands. Then I will tell what I would do in such situations, for educational purposes.


If a filter is installed in front of the entrance of cold water into the boiler, then you need to clean it. In addition, a separate filter element is installed in each gas boiler.

boiler, does, warm, water

I open my passport and see where it is installed. For example, Viessmann Vitodens 050 The filter stands right in the module of the duct sensor. Viessmann Vitopend 100 at the input of cold water into the boiler.

I cleaned the filter, I immediately check the duct sensor so as not to disassemble several times.

The sensor of the duct

Manufacturers put different duct sensors, but they work on two principles:

  • Like the Hall sensor: signals the presence and speed of the duct;
  • The Hoering sensor working as a magnet: a magnetic float swims on the chamber and acts on the Herkon.

I check the sensor, if it is broken, then I change it.

Here is a video where it is shown how to check the Navien duct sensor.

Heat exchanger

Then I remove the secondary heat exchanger and wash it. and other wealthy cities there are special flushing machines that can wash the heat exchanger without removing it. But I live in the village, no one has such a thing here, so I manually wash the heat exchangers with citric or acetic acid.

When washing the heat exchanger, do not use strong acids, such as: solar, nitrogen. Great risk to damage the heat exchanger.

I collect everything back and start the boiler. In 90% of cases, he begins to work as it should and warms up.

If you have a boutermic heat exchanger on your boiler, then check and rinse it once a year. They are very often clogged due to the fact that they have rather small passages.

If after that the wall gas boiler does not warm hot water, then check the darling pipes.


I had one case when a hot water water supply was clogged. This is a rarity, but this also happens.

Watch the video, I shot how to clean the filter and rinse the heat exchanger of the gas boiler.

Why does Navien Ace boiler heat hot water

In this article we will talk about the three main reasons why the boiler Navien Ice does not warm hot water. After reading our instructions, you can determine the faulty detail.

Navien Ace wall boiler is a sales leader in Russia. He deserved this title, thanks to his reliability and ease of installation. The manufacturer of this boiler is the Korean company Navien, which, thanks to the output of this particular model to the market, has become the seller of boilers number 1. In Russian federation.

Thanks to the modern body design, Navien Ace boilers look great in any interior. But, like any other mechanism, this boiler sometimes needs to be repaired.

The most common complaint about this model. Navien Ace boiler does not warm water.

This is manifested as follows: cold water enters the boiler, and at the exit from the boiler. water has either the same temperature, or slightly hot than at the entrance.

Of course, using such hot water is most inconvenient, so you need to deal with the problem.

Since we very often hear a complaint about the boiler gas navien ice, we have decided to tell you about the ways to solve this problem.

Traditionally. There is no one solution to the problem of lack of hot water.

Three modules are responsible for heating of sanitary water in the boiler: a heat exchanger in which water directly heats up, a hydraulic engine that switches the boiler from the heating mode to the water heating mode, and the water duct sensor. who understands that the flow of cold water began through the boiler, and it must be heated.

In this article, we will talk in detail about these three nodes, and list the list of actions that will help if your gas boiler Navien Ice does not warm water.

There are several main causes of this malfunction.

In this case, the boiler goes into the water heating mode, but hot water does not enter from the tap.

When clogging the heat exchanger, it is necessary to remove the heat exchanger, and clean it. If you notice damage in the heat exchanger itself. It needs to be replaced.

The second reason. This is the failure of the three.way valve. In this case, as when clogging the heat exchanger, when the boiler moves to the heating mode of the hot water, Navien Ace does not warm hot water. It is necessary to replace the valve. The main sign of this breakdown is the drop in the system.

The third reason that Navien does not warm the water. may be a breakdown of the water duct sensor. With this malfunction, the boiler cannot detect water duct through it. In this regard, the boiler does not pass into the heating mode of hot water, but remains in heating mode.

And now we will eliminate the malfunctions in the boiler.

About how to rinse and / or replace the heat exchanger. can be read in another article. Also. In another article, we talk in detail about the replacement and maintenance of a three.way valve.

Here we will tell in detail how to replace or repair the sensor of the boiler water duct.

With any manipulation with the boiler, before starting work, it is necessary to turn off the boiler from the mains.

To begin the analysis and determination of the cause of the boiler breakdown, it is necessary to block the gas valve.

Then you need to block the taps on the supply and return of heating and water supply, and drain the water from the boiler. To do this: remove the plug from the filter and drain the entire coolant from the boiler.

Then, having removed the fasteners from the water reinforcement, we take the sub.pipe to the side and take out the hydraulic station.

The cause of the hydroelectric complex malfunction can be covered in the sensor of the water duct, namely, the magnet installed inside the hydroelectric complex could stick or the rod went to the side and fell out of the water duct sensor.

In this regard, the boiler ceases to see the duct of the water, as a result of which the cauldron of the ice does not warm hot water. To solve this problem, it is necessary to replace the hydraulic node.

If you have any questions. Call us, or write in a chat on this page. We will be happy to help.

The effect of temperature on the properties of the coolant

In addition to the above factors, the water temperature in heat supply pipes affects its properties. This is based on the principle of operation of gravitational heating systems. With an increase in the level of water heating, its expansion occurs and circulation occurs.

However, in the case of the use of antifreeze, the excess of the norm in the temperature in heating batteries can lead to other results. Therefore, for heat supply with a coolant other than water, you should first find out the permissible indicators of its heating. This does not apply to the temperature of the radiators of centralized heat supply in the apartment, since such systems do not use antifreeze fluids.

Antifreeze is used if there is a probability of a low temperature on the heating battery. Unlike water, it does not begin to move from a liquid state to crystal.shaped when 0 ° C reaches. However, if the work of heat supply is included for the norms of the temperature table for heating in the larger direction, the following phenomena may occur:

  • Foaming this entails an increase in the volume of the coolant and, as a result, an increase in pressure. The reverse process when cooling antifreeze will not be observed;
  • The formation of lime plaque into the antifreeze includes a certain number of mineral components. In case of violation of the rate of heating temperature in the apartment, their precipitate begins to a larger way. Over time, this will lead to suction of pipes and radiators;
  • Increase in the density. Circulation pumps may be observed if its rated power has not been designed for such situations.

Therefore, it is much easier to monitor the temperature of the water in the heat supply system of a private house than to control the degree of heating of antifreeze. In addition, ethylene glycol compounds during evaporation, I release gas harmful to humans. Currently, they are practically not used as a coolant in autonomous heat supply systems.



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