Solving the problem of low hot water pressure from a gas heater

To bathe in hot water and avoid possible expensive repairs, you need to operate the equipment correctly, and also, for preventative purposes, periodically clean it from accumulated dirt. Scale, clogging, wear of filters - these and other factors can lead to weak pressure of hot water from the gas water heater or the household appliance to completely fail. I wouldn’t want to be left without hot water supply at the most inopportune moment, do you agree?

But what to do in case of low pressure, how to detect the cause and eliminate it? In this article, we will consider in detail possible problems that prevent the normal operation of the water heater, and methods for solving the problem. For clarity, we will supplement the presented material with photos and video recommendations.

What is the problem with low blood pressure?

There are many reasons why such a malfunction can occur. Among the most likely ones are problems with the tank, and sometimes various damage to the heat exchanger. However, in most cases, the reason for the pressure drop in a gas boiler lies in the non-working state of the make-up tap. It may not be closed tightly, or it may be completely faulty. Even minor mechanical damage to the faucet can cause a drop in pressure. Otherwise it is called a connected valve or fill tap. It is installed mainly on combined or double-circuit boilers. The fact is that the water supply system and the heating circuit communicate through an open or faulty fill valve, but this should not happen. The consequence of this is equalization of pressure, since the two systems are connected to each other. Typically, the internal pressure inside the water supply is much greater than it should be in a heating system. Therefore, through the hole this pressure quickly dissipates, and in the end it turns out that, in fact, the boiler and the water supply will have the same pressure.

At the same time, the boiler continues to operate, but the pressure indicators remain the same, since the water, expanding due to heating, flows into the water supply. As soon as we turn on the hot water, the pressure immediately drops. That is, due to an open tap, the boiler and water supply are essentially communicating vessels, trying to balance each other. This explains the strong unpleasant smell, because before water flows out of the tap, it passes through the water supply system, into which the already used water is drained. But as soon as you turn off the hot water, the pressure in the entire system returns to normal. It returns to the state it was in when cold water entered the house. But the pressure in the boiler remains low, since water fills the boiler through the same feed tap.

It follows that this problem causes the tank to constantly fill and empty. This is very harmful for the entire system, and there are two reasons for this:

• Oxygen that tap water brings with it. It oxidizes all pipes, which leads to their malfunction. Metal corrosion has a very negative effect on it, which can ultimately lead to serious problems. Pipes subject to corrosion are destroyed and after some time water begins to pass through them. Repairs can be very expensive since all the equipment will have to be replaced. A constant flow of fresh water reduces the service life of equipment by five to ten times.
• Salts contained in large quantities in the same water. They lead to the formation of scale, and this is also not beneficial for the boiler. It will be almost impossible to clean this scale from the pipes without damaging them. Leading manufacturers of heating equipment strongly recommend that the make-up should not be greater than the volume of the boiler, tripled.

Possible causes of low pressure

To figure out why there is no pressure in the gas water heater, you should determine the main possible causes of the problem. And also the factors that influence it.

Factors:

• Speaker power. Without it, good pressure cannot be achieved. The problem occurs if the indicator is less than 8 kV. It must be from 10 kV.
• Blockages. If scale and other substances accumulate in the pipes, water does not flow. Therefore, filters should be checked.
• Scale formation. It can collect in the heat exchanger and go into tubes. If water with detached pieces gets into them, a blockage occurs.
• Past technical work and neglect of pollution prevention.

Causes:

• Weak pressure of hot water in the tap appears due to the fact that the filter is clogged. To solve the problem, remove it from the heat exchanger inlet and brush it with a brush under water pressure. If damaged, be sure to replace it.
• Scale has formed. You can use proven home remedies to get rid of dirt that will not damage the material. The most popular and effective is citric acid. If hot water flows poorly, it is not necessary to use aggressive special cleaning liquids.
• There is a blockage. Water does not flow well into the pipe. To eliminate this, a reverse flow of cold water is started.
• Problem with the mixer. Small debris can get in there. To solve it, it is recommended to check the filter and rubber hose. And then check how hot water flows from the tap.

Each of the problems is worth considering in more detail.

Filter clogged

The insides of the water heater gradually become dirty due to the operating principle of the device. Soot and deposits accumulate due to heating with gas. Due to poor water quality, the filter becomes clogged. It slows down the scale formation process by about 50-60%. However, it gradually becomes clogged, becomes unusable and even breaks.

How to return water pressure from a gas water heater if the problem is in the filter:

• Use a stiff brush to remove anything that has clogged the holes. These are salt deposits, small pipe debris.
• Rinse it with water under pressure. Then place in a separate small container.
• Fill with filter cleaner.
• Leave for half an hour. During this time, all deposits will move away from the walls.
• Rinse under running water to get water everywhere.

If the column is clogged, preventive measures should be reviewed.

If the pressure is very weak and the filter gets clogged often, you need to follow the rules:

• It is recommended to make the water soft.
• Regularly inspect the condition of the parts of the column and clean them, even if the pressure has not dropped.

Important! If possible, install an automatic water softener.

Scale in the heat exchanger

Scale in the heat exchanger of a gas boiler should not be cleaned mechanically. There is a risk of damaging the surface of the coil from the inside. Because of this, a layer of plaque will appear again.

What products are used for processing:

• Household chemicals and substitute materials at hand. Citric acid is popular. A similar result can be obtained by using vinegar diluted to 7%. After cleaning, the pipes are washed with a soapy water solution.
• Calcium deposits will be removed by Silit and other similar products.

Important! Hydrochloric acid cannot be used. It will destroy the protective layer and lead to failure.

What to do to prevent scale from forming:

• Install a deep-cleaning main filter for the cold water supply and poor water pressure will not often bother you.
• Purchase a water filter to reduce water hardness. It changes the chemical composition of the liquid. Reduces the amount of scale by 40-60% and the cold water pressure does not decrease.
• Install a magnetic filter. It retains calcium salts.

How to clean the heat exchanger if the hot water pressure disappears:

• Disconnect the tubes carrying the liquid. Unscrew the nuts using a special solution that helps with rust.
• Pour descaling agent into the heat exchanger using a funnel. For 0.5 liters of water you will need 100 g of citric acid.
• Discard the water in the morning. Rinse with clean liquid. Make sure the walls are clean.

Important! When using a special cleaning product, you should make sure that it is suitable for all surfaces, even ceramics.

Home remedies for scale deposits often include drinks such as Cola or Fanta. This is undesirable in the case of pipes. Soda helps to renew the kettle better and is also not suitable for this problem. For the coil, they often buy a Zhuk sprayer and orthophosphate acid.

Blockage in pipes

The water pressure in the tap weakens if there is a blockage in the gas water heater tubes. The problem can be corrected by reversing it.

In order for the back pressure of cold water to push through the blockage, you need to take several steps:

• Remove the plug.
• Place a container under the device to catch the draining liquid.
• Open the taps.
• Close the spout.

Using the secret may solve the problem of poor hot water pressure in the kitchen. But practice shows that this problem appears relatively infrequently.

Carefully! When working with liquids for cleaning pipes and other surfaces, you need to wear gloves to avoid burns and allergic reactions.

Faucet malfunction

Insufficient water supply to the tap indicates a problem with the mixer. Low pressure is a consequence of contamination with small debris. It can be located in a filter, a transmission box, or a thin rubber hose. The problem can be solved by disassembling the mixer and weekly visual inspection. You can remove dirt with running water.

Important! If the hot water pressure drops too often, you should contact a specialist.

A faucet is a device that is responsible for opening and closing the flow of water. It also regulates the pressure and sets the desired temperature.

Norms and methods of control

To begin with, we will briefly consider the types of pressure and methods of measuring it, which will help to better understand how it is formed in the heating circuit and the hot water supply (DHW) circuit.

Types of pressure and its norms in a gas boiler

In both single-circuit and double-circuit heating systems, the pressure is:

• static - natural pressure generated by gravity acting on the coolant (each meter of the height of the system riser creates approximately 0.1 bar);
• dynamic - artificial pressure created forcibly in a closed circuit (by a pump or expansion of a heated coolant), depends on the parameters of the pump, the temperature of the coolant and the tightness of the system.
• working - real pressure (static + dynamic), it is this that is measured by instrumentation, values ​​of 1.5 or 2 bar are considered normal;
• maximum - the maximum permissible for the operation of the system, even a short-term excess of it (water hammer) can most likely lead to emergency depressurization of the system (in other words, rupture of pipes, radiators or boiler heat exchanger).

How is it measured?

Most models of wall-mounted and floor-standing gas boilers have a built-in pressure gauge that measures the operating water pressure in the heating circuit. But even if it is available, it is recommended to install an additional one: as part of the safety group (pressure gauge/thermometer, safety valve, air bleed valve).

The fact is that even a dial factory pressure gauge can fail over time and measure pressure incorrectly or show pressure surges, not to mention electronic sensors. An additional control and measuring device installed on the boiler supply will allow you to quickly check and compare the readings in order to immediately rule out a malfunction of the main pressure gauge.

How to pump up a boiler expansion tank

A
Connection for draining water into the central heating circuit (CH)

IN

Connection for draining water into the hot water supply circuit (DHW)

WITH

Gas supply fitting

D

Connection for cold water supply

E

Connection for supplying water from the central heating circuit

S

Safety valve output

T

Drain tap

F

Filling tap

How to properly pump air into the expansion tank

We follow the specified order

1. Close all boiler, supply and return taps. 2. Open the drain fitting in the boiler. (T) Drain the water from the boiler; the pressure in the boiler should be zero.

3. We connect the pump through the spool, the drain fitting is open, there should be no water in the expansion tank. You can use any pump, since there is a car spool there and you will also need a pressure gauge to measure pressure, also a car one - I used a car compressor. True, for this I had to drag the battery home, but with an electric compressor, be careful to turn it off in time and not to overpump. 4. The pump needs to pump air until water stops flowing from the drain fitting. At this stage, the main goal is to free the Tank from water 5. We release the pumped air. 6. Inflate again, controlling the pressure with a pressure gauge. The pressure in the expander should be within 1.1-1.3 bar. (see passport, often indicated) 7. Close the drain fitting. 8. Open all the taps to the boiler - everything that was closed. 9. We feed the boiler through the make-up tap (F) to a pressure of approximately 1.2-1.5 bar. 10

Let's start the boiler. If people do not live permanently in the house where the double-circuit boiler is located, only on short visits, then it is important to pay special attention to the required pressure. Imagine this picture. No one is home for a long time, the lights go out, and accordingly the boiler also turns off, the water cools down - the pressure in the system, due to weak pressure in the expansion tank, drops below the boiler switch-on threshold

The electricity turns on, but the boiler does not start, the pressure has dropped too much. You arrive a week later and find your house frozen, the frozen water in the pipes and radiators mercilessly tearing them apart. An ice age is coming for you. Therefore, it is better to be safe than sorry

No one is home for a long time, the lights go out, and accordingly the boiler also turns off, the water cools down - the pressure in the system, due to weak pressure in the expansion tank, drops below the boiler switch-on threshold. The electricity turns on, but the boiler does not start, the pressure has dropped too much. You arrive a week later and find your house frozen, the frozen water in the pipes and radiators mercilessly tearing them apart. An ice age is coming for you. Therefore, it is better to be safe than sorry.

A home heating system without the required pressure indicator will not work correctly. In addition, losses and pressure drops negatively affect the functioning of equipment and lead to breakdowns. When the pressure in the heating system drops, the reasons that caused these surges should be immediately eliminated.

How to solve the pressure problem?

The very first thing to do in such cases is to check the valve. Before starting the test, make sure that the make-up valve is closed as tightly as possible. Check what happens when the gas boiler is turned off. To do this, disconnect it from the power supply. The same thing happens even when it is turned off - there is only one solution - call a service center that will replace the faucet for you. It is not recommended to replace the faucet yourself at home, as this work may require special equipment.

If the pressure drops only while the boiler is on, and this does not happen while warm water is being used, but only when the boiler is turned on and off, then the cause of the breakdown is most likely in the expansion tank. You can easily fix the problem yourself, at home. It is enough to find a fault by external inspection, most often it is some kind of scratch or small hole, then patch it with special glue. If the hole is large, then repairing it will require the help of specialists or a complete replacement of the expansion tank.

Malfunctions of the pressure gauge and boiler automation

If all possible reasons for the decrease in pressure in the system have been eliminated, and the boiler continues to go out due to low readings on the pressure gauge, you need to make sure that it is working properly. This measuring device can only be tested using special equipment, so you cannot do without calling specialists.

In some cases, the problem lies in the central control board, which generates incorrect signals that affect the pressure in the system. A complete diagnosis will be required that will answer all questions.

Causes of pressure drop

There are many factors that explain why blood pressure drops. Among them:

1. Coolant leaking from the heating system.
2. Power outages for a long time.
3. Problems in the operation of the expansion tank.
4. Incorrect selection and operation of equipment.

When the coolant pressure decreases, the heating unit stops functioning because water does not enter the tank. If the gas pressure decreases, the system automatically turns off. To prevent such troubles, it is necessary to timely service the boiler and take measures when it is turned off.

Pressure drops when hot water is turned on

If the pressure in the heating system drops when hot water is turned on, this may be due to air leaks into the heating circuit or malfunctions in the 3-way valve. A similar problem is associated with the special structure of boilers.

We recommend reading: How to heat a stove with coal, a simple algorithm of actions and tips from stove makers

When figuring out what to do if a wall-mounted boiler begins to release pressure when you open a hot water tap, it is important to understand the specifics of its operation. To successfully eliminate defects, you should seek help from a specialist.

Formation of air jams

If cracks appear anywhere in the system and depressurization occurs, this leads to coolant leakage and air suction into the circuit. As a result, air bubbles form. Their appearance is also facilitated by incorrect filling of the circuit, which leads to sudden pressure surges. To troubleshoot problems, it is enough to carry out the procedure for de-aerating the installation by installing vents.

Expansion tank defects

The reasons for the pressure drop in a gas boiler include problems with the expansion tank. There may have been a rupture in the structure or depressurization of the nipple, causing it to leak air.

On the inside of the container there are 2 compartments with a membrane partition. One part contains air masses, and the second contains coolant. As the liquid consistency warms up, it expands and increases in volume, beginning to exert great force on the membrane. Under this influence, the membrane leads to compression of the gas mixture.

With prolonged use of the system, the nipple wears out, so it does not cope with its task.

If the Navien boiler has a problem, you will need to purchase a new tank and replace it. However, before purchasing, you need to make sure that the problem is related to this factor. Cases of leaking pipes, radiators or airing of the heating circuit cannot be excluded.

If the membrane is damaged, the expansion tank ceases to cope with its tasks, and the pressure level decreases. To detect this defect, just knock on the structure (the sound will become dull). And when you briefly press the nipple, water will spill.

Safety valve defect

The task of the safety valve in the Navien boiler is to protect the heating system from excess pressure. If the permissible values ​​are exceeded, the part opens and begins to discharge excess water. The standard response threshold is 2.5 bar.

If the valve is not selected correctly, many false alarms will occur, causing the pressure to continually drop. To fix the problem, you need to replace the valve.

While still using this element, particles of dirt, scale and other debris may accumulate under the seat, preventing it from closing freely. You can try to get rid of the problem yourself by twisting the valve cap in a given direction.

Next, you should monitor the pressure readings using a pressure gauge for 1-2 hours. If the situation has not changed, you will need to find another cause of the breakdown.

Leaks in the heating system

Constant leaks in the heating circuit are one of the key reasons why the pressure has dropped. The rate of decline is determined by the degree of failure. Sometimes the pressure is released instantly, and in other cases it is released slowly and gradually. If the leak remains visible, it can be identified by water puddles or the appearance of condensation on the surface of the walls.

If there are leaks in pipes and radiators, you may not notice them, since the coolant can evaporate during operation of the equipment. When the boiler is turned off, if there is a leak, a puddle will appear under it.

If there is a decrease in pressure in the heating system, but it is not possible to find the cause of the problem, you will need the help of an experienced specialist who will confirm that there are no leaks and will repair the Ariston, Baksi or other model gas boiler.

Problems with measuring equipment

Sometimes pressure gauges give erroneous readings. Low pressure readings on the measuring equipment may be due to a malfunction of the device itself. If there are no visible defects, it is worth checking the automation and instrumentation. During operation, they may fail and display incorrect values.

Finding such an error on your own is not easy, so it is recommended to take professional help from specialists.

Pressure drops due to leaks

To eliminate this type of problem, the owner needs to diagnose and inspect the entire heating system, since liquid can escape through any component.

The cause of the leak may be a loose connection, worn-out heat exchangers, cracks in pipes and batteries. Most often, the level of tightness is checked when the circuit is put into operation, however, the tightness can be compromised during operation itself.

Nodes that need to be inspected and checked first:

• connecting fittings;
• radiators;
• expansion tanks;
• double-circuit boilers.

Detected problems must be corrected, after which the system will be recharged with liquid until the normal pressure level is restored.

Air jams

The formation of cracks and depressurization of the heat supply system leads not only to leaks, but also to the opposite effect - the suction of air masses into the circuit. The result of this is the formation of air bubbles.

Low blood pressure may occur due to air pockets

Bubbles also form when the circuit is not filled correctly, which is why air pockets appear in it, causing a significant drop in pressure.

Recommendation! This problem is solved by simply de-aerating the system, thanks to the installation of bleeders.

Problem with expansion tank

There are cases of problems with expansion tanks. A gap forms here or the nipple may leak air. The inside of the tank consists of two compartments separated by a membrane. One compartment contains air, and the other is filled with coolant. When the liquid working medium is heated, it expands and presses on the membrane with greater force. The membrane, in turn, affects the compression of the gas mixture.

When the equipment operates for a long time, the nipple wears out and begins to leak air, which leads to a decrease in pressure.

A problem with the expansion tank may cause pressure changes

The only solution to this problem is to completely replace the tank, however, before doing this, you should make sure that the problem lies precisely in this, and not in leaking pipes, radiators and airing of the system.

Cracks in the heat exchanger in the boiler

Over time, microcracks can form on the walls of heat exchangers, allowing water to pass through from the heating system. Since the water in the boiler evaporates quickly, it is by no means easy to identify this breakdown yourself in the same way as in the previous situation. In addition, cracks can occur during washing, which is carried out for prevention or due to manufacturing defects. This problem is eliminated by sealing the detected area with a crack.

Over time, microcracks may appear in the walls of the heat exchanger

Measuring equipment malfunction

Sometimes diagnosing a system for the integrity of its components may not yield results. If you have not been able to find a visible cause, then you should think about checking the proper operation of the boiler automation and control equipment. This equipment may break down and give incorrect readings.

It is quite difficult to determine this type of malfunction on your own, so it is better to seek help from specialists. The problem is solved by replacing control and measuring instruments.

The coolant drain valve is not closed tightly

Sometimes the reason may lie in a completely simple issue, such as a faucet that is not clamped tightly enough, due to which the pressure level in the unit decreases. The problem can be fixed easily and quickly by tightening the tap.

What to do?

The problem can be solved by adding fluid to the system, but first the leak itself must be eliminated.

To do this, follow these tips:

1. Leak in the radiator section - turn off the heating, drain as much water as possible, and then disconnect the battery. Mark the location of the leak, dry it, clean it and seal it using cold welding. If the hole is too large, then you can simply remove this section by separating them from each other.
2. Leaking in a panel radiator - you can try to seal the leak by cold welding, but in most cases you will have to replace the panel with a new one.
3. Leaks at the joints - the soldered structures are cut off, and a blank suitable in size is made from a new piece of pipe. Soldering is performed using a special soldering iron.
4. Leaking faucets - replacing the element with a new one.

Expert opinion

Grebnev Vadim Savelievich

Heating system installer

If there is a leak in the boiler itself, where the water is heated, then you must call specialists so that they can diagnose and carry out repairs. Without skill, experience and appropriate permission, making adjustments to the operation of gas equipment is extremely dangerous.

Control devices

To control the water pressure in the heating boiler and heating system, pressure gauges and thermomanometers are used. The latter are combined devices for monitoring two parameters at once. After starting the circuit, it is necessary to monitor the indicators so that they do not go beyond normal limits.

Some double-circuit floor-standing and wall-mounted boilers do not have traditional dial pressure gauges. Instead, electronic sensors are installed here, information from which is transmitted to the electronic unit, after which it is processed and displayed on the display. Another approach is also possible - if the heating unit does not have a pressure gauge, it is provided by the safety group.

The security group itself includes the following nodes:

• Pressure gauge or thermomanometer - for monitoring temperature and pressure in the heating circuit;
• Automatic air bleeder – prevents the circuit from becoming airy;
• Safety valve - relieves coolant pressure when it increases excessively.

Be sure to provide this unit in a closed heating system.

CALCULATION OF MEMBRANE EXPANSION TANK

In some cases, the pressure drop in the heating system is associated with the wrong choice of a double-circuit boiler. Thermal calculations take into account the area of ​​the premises that need to be heated. Based on these conditions, the power of the heating device is selected. The calculation takes into account ordinary radiators, in which the volume of water is not very large. And if metal pipes are used instead of radiators, several times more liquid is required to fill them, and accordingly, the volume of expanded water will also be increased.

The expansion tank in double-circuit boilers is usually 6-8 liters. It is designed for approximately 120 liters of water in the heating system. This is quite enough for radiators. But what can happen if there is more water in the system than it should be according to calculations. Let's say that the liquid, heating up in the pipes, expands and fills the standard expansion tank. But the size of the tank is not enough to remove excess heated water, the pressure rises and an emergency release occurs through the safety valve. After the boiler turns off, water from the tank comes back into the system, but since the boiler had an emergency discharge, there is not enough liquid in the system, the pressure drops below a critical level. That’s it, without replenishing the system with water (that is, without human intervention), the boiler will not turn on. If the air temperature outside is low, defrosting of the system is ensured. Moreover, this can happen at the most inopportune moment.

Now automatic water rechargers have appeared on sale, which supply water to the system if the pressure in it drops below a certain level

Homeowners who leave their homes unattended for long periods of time should pay attention to them.

Typically, heating installations occur during the warm season in order to have time to prepare for winter. During startup, the boiler operates in medium mode, and it is still warm in the fall. Therefore, when the heating is not so intense, the liquid expands slightly, the pressure in the system is within normal limits. But when frost comes and the boiler starts working at maximum load, the volume of heated liquid increases, and then it turns out that the standard expansion tank is not enough. To prevent such a scenario from happening, you need to correctly calculate the heating system and install in time an additional membrane expansion tank, which is used in closed-type heating systems when the fluid moves under pressure created by a circulation pump.

It is difficult to determine the exact amount of water in heating pipes; this is usually done by power: it is multiplied by 15. For example, a 17 kW boiler has a heating system that holds 255 liters of water. There are methods to help calculate the volume of the expansion tank. The following calculation is suitable for heating systems installed in one-story houses.

Volume of the expansion tank = (V*E)/D, where V is the volume of water in the heating system, E is the expansion coefficient of the liquid, D is the efficiency of the expansion tank.

D = (Pmax—Ps)/(Pmax +1),

where Pmax is the maximum operating pressure of the heating system, equal to an average of 2.5 bar;

Ps – expansion tank charging pressure equal to 0.5 bar.

D = (2.5-0.5)/(2.5 +1)=0.57

So, for a 17 kW boiler, the volume of the expansion tank = (255*0.0359)/0.57=16.06 l.

The technical documentation says that the 17 kW device has a built-in expansion tank with a volume of 6.5 liters. For proper operation of a double-circuit boiler, it is necessary to install an additional expansion tank with a volume of 10 liters in the heating system.

How to determine whether an additional expansion tank is working in the system or not? To check it, pump up the air pressure with a pump, for example, up to 2 bar, and provide access to the nipple. Let's connect it to the heating system. Let's turn on the boiler. As the water heats up, the pressure will rise. If it increases to 1.8 bar, bleed the air from the expansion tank through the nipple, while looking at the boiler pressure gauge. As soon as the pressure in the tank drops below 1.8, water from the system will begin to enter the tank, and the pressure gauge needle on the boiler will show a decrease in pressure. This means that the additional expansion tank is installed correctly and is working correctly. Finally, you need to pump up the pressure to the desired level, for example, to 1 - 1.5 bar. That's all. If you liked the article, share it on social networks.

How to increase the pressure in the boiler

If the reason is a malfunction of the expansion tank, then its volume was calculated incorrectly or the membrane was damaged. In this case, you should either more accurately calculate the required volume, or simply replace the tank.

If the pressure begins to drop immediately after the initial start-up, then this is normal. There is a large amount of air present in a circuit that has recently been filled with tap water. Over time, it will turn into bubbles and be removed from the pipeline, and the circuit parameters will return to normal. To remove bubbles faster, use a manual air release.

We recommend reading: Review and characteristics of gas boilers

Before increasing the pressure, it is necessary to check the tightness of the system

Before carrying out measures to increase the pressure in the system, it is necessary to ensure its tightness. To do this, you need to inspect the following parts of it:

• heating appliances - leaks often appear at the junctions with pipes, and leaks that occur between separate sections are also possible;
• pipes - even very small cracks can often lead to coolant leakage;
• fittings - often cause leaks;
• boilers - models with two circuits have a complex internal structure: for example, you should carefully inspect the circulation pump, three-way valve and heat exchanger.

How to recognize?

The sequence of actions is as follows:

1. Check for cold water in the pipeline.
2. Pay attention to the smell of hot water (when using a double-circuit boiler). If it smells unpleasantly of rust and mustiness, and has a yellowish or gray tint, then this water is definitely from the heating system.
3. Check whether the tap valve for recharging the system is closed.

Expert opinion

Grebnev Vadim Savelievich

Heating system installer

You also need to check the serviceability of the feed tap itself. If the pressure in the system does not change when it opens and closes, then the mechanism needs to be replaced.

Water heating system design

Water heating system
The method of heating a house using a liquid coolant (water, or water-based antifreeze) today is one of the most thorough and reliable schemes: water is heated in a boiler, transferred to heating radiators, transfers thermal energy to the air space in the house and completes the cycle by returning to the cauldron.

The owner of a private house most often uses natural gas to power the boiler, but can also use wood, coal or kerosene. The design of the heating circuit consists of key components - boiler, pipes, heating radiators - and auxiliary components - expansion tank, hydraulic pump, thermostats, valves.

In a modern home, in most cases, automated boilers are installed. The control panel allows you not only to turn the boiler on and off, but also to set parameters for its optimal operation.

How to eliminate clocking of a gas boiler in DHW mode

For heating and hot water supply of apartments and small private houses with one bathroom, double-circuit gas boilers are usually used. The owners of such boilers are often faced with the fact that either cold or hot water flows from the tap. As people say, the boiler clocks, the boiler's DHW mode periodically turns off and then turns on again.

The principles of adjustment and adjustment of the hot water supply system described in this article are suitable for double-circuit gas boilers of many brands and manufacturers, as well as gas hot water heaters.

Preparing water for the heating system

The higher the hardness of the water, the worse it is for heating - scale leads to overgrowing of the gaps in the pipes, damages the boiler heat exchangers and kills the pumps.

Cleaning the system from scale is an extremely difficult task that takes several days. It’s easier to make an effort once to properly prepare the coolant for heating.

Soft water is not available everywhere, but hard water can be softened at home before adding it to the system. For this purpose, special filters – softeners – are purchased.

There is also no need to try too hard when softening water, because soft liquids have higher acidity, and this leads to the release of carbon dioxide and corrosion of metals. Antifreezes containing glycol also have high acidity. Additives - inhibitors (silicates, amines, phosphates and others) help reduce its harmful effects.

Good acidity: 8.5 – 9.5 pH.

Recipe: You can mix tap water with distilled water in a 1:1 ratio.

After mixing, the resulting liquid must be boiled (to remove oxygen from it).

Do not use chemical additives to soften water.

Their use destroys seals, and when heated, processes occur that are destructive even for metals.

So, if the pressure fluctuates or is consistently low, the search for the problem should begin by inspecting the pipeline for leaks. Then check the performance of the pumps by measuring the static pressure. In order not to encounter the problem again, you need to install air vents everywhere and spare no effort in preparing the coolant with an optimal pH.

Access to the service menu of the Protherm boiler

The electromechanical devices of the boiler (electric valves, stepper and conventional electric motors, sensors) are controlled by a microprocessor of the electronic control board in accordance with the programmed program.

The boiler operating program settings can be changed on the control panel using two menus - a public user menu and a hidden service menu.

Access to the service menu of the Gepard boiler

The Protherm Gepard boiler is controlled from the control panel through a publicly accessible user menu. How the owner can operate the boiler is described in the operating manual.

On the control panel you can call up another, hidden menu - a service menu intended for specialists. The service menu becomes available on the display screen after entering the code.

Press and hold the mode button (1) for about 7 seconds; The display will change and the number 0 . — Using the + or — (2), enter the code, number 35 . — Confirm entering the code by pressing the mode button (1). After this, the display will show the 1st line of the menu in the form of symbols alternating on the screen: d. 0 .

— Using the + or — (2), enter the number with the required menu line number: d.** .

To change the value of a parameter in the menu bar: - Press the “mode” button to move from the menu line number “ d.** ” to the parameter value (the display alternates between the “=” symbol and the parameter value). — Change the values ​​of the displayed parameters using the + or — buttons (3) on the boiler panel. — 3 seconds after the change, the new values ​​are automatically confirmed. To return the display to its original state, press the “mode” button for 3 seconds. After 15 minutes of inactivity, the display returns to operating mode on its own.

Access to the service menu of the Panther boiler

The control panel of the Protherm Panther boiler has some differences from the Protherm Gepard boiler. The boiler control panel has a hidden service menu, which becomes accessible when the code is entered.

Boiler control panel Protherm Panther (Panther)

To access the service menu of the Protherm Panther boiler, you must: Press and hold the mode button (1) for about 7 seconds; The display appearance will change. — Using the buttons on the left + or — (2), enter the access code to the service menu — number 35 in the left half of the display. — Confirm entering the code by pressing the mode button (1).

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After this, the display will display the 1st menu line in the form of symbols d.00 with the menu line number in the left half of the display, and the numerical value of the line parameter in the right half of the display. — Using the buttons on the left + or — (2), enter the number with the required menu line number: d.** .

To change the value of a parameter in the menu bar: - Change the values ​​of the displayed parameters in the line using the buttons on the right + or - (3) on the boiler panel. — 3 seconds after the change, the new values ​​are automatically confirmed. To return the display to its original state, press the “mode” button for 3 seconds. After 15 minutes of inactivity, the display returns to operating mode on its own.

The service menu commands and the procedure for setting the power of the Protherm Panther boiler are similar to those given for the Protherm Gepard boiler.

Description of some service menu commands

Line d.36 - shows on the display the hot water consumption measured by the flow sensor, l/min. when dispensing hot water (read only).

Let's determine the consumption of hot water in our apartment (in the house). Line d.36 of the service menu shows on the display the hot water flow measured by the flow sensor, l/min. We display line parameter d.36 on the display, then open the hot water taps in the apartment (in the house) one by one to full flow and record the water consumption readings from the display.

Line d.52 - setting the minimum power of the boiler burner by shifting the minimum position of the Honeywell gas valve stepper motor. The range of possible parameter values ​​is from =0 to =99. The lower the parameter value, the weaker the intensity of gas combustion.

Line d.53 - setting the maximum power of the boiler burner by shifting the maximum position of the Honeywell . The range of possible parameter values ​​is from =0 to =-99 (negative values ​​with a minus sign). The lower the parameter value, the weaker the intensity of gas combustion.

Line d.88 - Protection against water hammer in cold water distribution (for KTV and KOV boilers). The ability to change the parameter eliminates the reaction to water hammer, which in some cases occurs in cold water pipelines. For example, when the automatic valve in the flush cistern of a toilet (or washing machine, or dishwasher) closes, a pressure surge (water hammer) may occur in the water supply pipes. The consequence of this may be a false activation of the flow sensor (turbine) of tap water, which will lead to a short-term unwanted activation of the boiler’s DHW mode. Factory setting 0 = activation of the ignition process for heating tap water at a flow rate of 1.5 l/min. Changing the parameter to value 1 = activation of the ignition process for heating tap water at a flow rate of 3.7 l/min. In this case, the flow duration should be at least 2 seconds.

Line d.96 - Setting the boiler to the parameters set from the factory. If the settings lead to incorrect operation or failures, it is possible to restore the boiler to factory settings. Setting: 0—replacement with factory settings will not be performed; 1 - will be returned to factory settings Note: when entering the setting of this parameter, the display always shows parameter “0”.

Setting, adjusting the minimum power of a boiler with a Honeywell gas valve

The boiler manufacturer Protherm Gepard (Panther) installs the SIT 845 Sigma gas valve on some versions of the boilers, instead of the Honeywell gas valve. The setting of this valve is described above. In the service menu of Protherm boilers with a SIT valve, lines d.52 and d.53 are missing.

Setting the maximum gas pressure:

On the boiler display we set the maximum hot water heating temperature to 60 °C.

We remove the lid from the boiler and provide access to the gas valve and the ability to observe the height of the flame in the burner. I recommend connecting a U-shaped pressure gauge to the measuring fitting at the valve outlet.

Turn on the DHW mode on the boiler by opening the hot water tap to full flow with maximum water flow (horn in the bathroom 6 l/min).

In the service menu, select line d.53 , press the “mode” button and see on the display the value of the gas valve stepper motor position parameter in maximum power mode. For example, on a new boiler, the factory setting for the maximum power parameter in line d.53 was = -17.

Step by step we reduce the value of the parameter in line d.53 and record the result. For example, set the line = -30 (minus 30 is less than minus 17) and click “mode” for the changes to take effect. We look at the height of the flame in the burner and the gas pressure. They haven't changed.

Next, we repeat everything with the parameter in the line =-40. If there are no changes, then reduce the parameter again.

The purpose of the adjustment is to find the limit where a further decrease in the parameter in line d.53 leads to a decrease in the flame height in the burner and to a decrease in gas pressure at the measuring fitting. In our example, the flame height and pressure began to decrease when setting the parameter in line d.53 to less than = -70 (remember, factory setting = -17)

As a result, the right border of the working area in the diagram will shift to the left, to a point with coordinates, for our example, 60 °C and 6 l/min. The maximum boiler power will decrease.

Setting the minimum gas pressure in front of the burner:

To adjust the gas valve, the boiler operation is switched to DHW mode. To do this, open to the minimum passage with a flow rate sufficient to turn on the boiler burner.

In the service menu, select line d.52 , press the “mode” button and see on the display the value of the gas valve stepper motor position parameter in minimum power mode. For example, on a new boiler, the factory setting of the minimum power parameter in line d.52 was = 72 and the burner was clocked in DHW mode.

We carry out experiments - we reduce the value of the parameter in line d.52 =60, click “mode” for the changes to take effect, and check the result. If the clocking has not stopped, then we further reduce the parameter in line d.52 =50 and observe the change in the temperature of the hot water in the tap. So, step by step, we reduce the parameter in line d.52 until we achieve no temperature fluctuations at a comfortable water flow.

We reduce the clock rate to an acceptable comfortable level. Do not attempt to reduce the minimum gas valve outlet pressure too much. Very low gas pressure on the burner can lead to disruption of combustion stability, to the failure and extinction of the flame.

For example, on a new boiler, the temperature of hot water in the tap reached 52 °C, after setting parameter =30 in line d.52 (remember, the factory setting was =72). There were no signs of burner clocking in DHW mode when the flow rate varied over the entire range, from the maximum (6 l/min) to the minimum 1.5 l/min. The temperature of hot water can be adjusted with a mixer, changing the water flow and mixing it with cold water within limited, but quite comfortable limits.

How to prevent air from entering the heating system

It is very difficult to completely avoid air getting into the system, but you can minimize the problem and learn how to easily and quickly remove traffic jams:

1. It is necessary to monitor the serviceability and tightness of all joints, shut-off valves, etc.
2. Before starting the system, air is pumped into it using a compressor at a pressure 20% greater than the working one. Measurements from the pressure gauge are taken at the beginning of the test and after 20 minutes. If the indicator has not changed, there are no leaks, the system is sealed. A leak will be indicated by the pressure gauge needle, as well as a characteristic whistle. To finally make sure that the leak has been found, lubricate it with a thick soap solution.
3. The system must be filled with cold water and smoothly. After filling, the air is released several times using air vents and Mayevsky taps. Each time after draining, water is added to the system.
4. It is recommended to use stainless or bimetallic heating radiators.
5. It is also advised not to change the coolant too often. A fresh portion of water always contains oxygen impurities.
6. To bleed air, install air vents in all problem areas and use them regularly. Or equip radiators with automatic devices and monitor their serviceability.

The adaptation period of the system, during which it is necessary to bleed air and add water again and again, is several days.

Setting the boiler burner power in DHW mode

In order for the boiler in DHW mode to heat water evenly and not cycle even with minimal water consumption, it is necessary to reduce the burner power by reducing the gas supply by adjusting the gas valve. Thus, the entire work area in the diagram will move to the left. To do this, reduce the factory settings on the gas valve for the minimum and maximum pressure at the gas outlet from the valve, in front of the burner.

As a result of adjusting the gas valve, there will be no signs of burner clocking in DHW mode when the hot water flow rate changes over the entire range, from the maximum (6 l/min) to the minimum specified in the instructions (1.5 l/min). The temperature of hot water can be adjusted with a mixer, changing the water flow and mixing it with cold water within limited, but quite comfortable limits.

Expansion tank operation

Pressure stabilization equipment has a membrane that is designed to separate air and working space. The function of the expansion tank is to accept the excess volume of water generated during the expansion process when exposed to elevated temperatures.

After the first task is completed, the water must be returned to the system. When the coolant expands, the pressure in appliances and pipes increases, and excess water flows into the tank. This provokes stretching of the membrane, as a result of which the volume of air decreases, which leads to an increase in pressure. When the water temperature drops, the pressure decreases, and the water that was previously in the tank is pushed out of it.

Which geysers operate at low pressure?

If the reason for the low pressure of hot water is not in the gas equipment, but in the water pipes, the problem can be solved either by normalizing the pressure in the pipes, or by purchasing a gas water heater that will function properly even with poor water pressure.

Modern geysers, which are equipped with a water pressure control device, can cope with this task. They work according to the following principle: the stronger the water pressure, the higher its temperature, and vice versa. Thus, if you set the minimum water temperature, the column will turn on even with low pressure. However, if problems with hot water pressure are constantly observed, it would be more advisable to equip the system with a pump.

The pressure in the gas unit drops; standards according to indications

To understand how to raise blood pressure, you need to be able to distinguish normal indicators from critical ones. What should be in a gas unit:

• for an open thermal system the normal is 0 bar;
• for closed – from 1.5 to 2 bar.

With an open heat supply, the hot liquid rises because there is a high pressure in the boiler, and a low pressure in the batteries. The hot liquid rushes there according to the laws of physics. This happens all the time, causing the rooms to heat up. An expansion tank and circulation pump are not used in such systems.

Diagram of an open heating system

With a closed heating supply, where liquid or antifreeze circulates in the pipes due to pressure in the expansion tank. The transmission is carried out using a circulation pump.

If the readings differ from normal even by 0.1 bar, then we can say that the pressure in the double-circuit (or single-circuit) heater is falling. A dual-circuit gas device has two functions: it heats the premises and at the same time heats the supply water.

Questions and answers

I often hear gurgling sounds in the expansion tank, after which the pressure on the pressure gauge drops slightly. After a while, when the boiler turns on, the pressure equalizes. What could be the reason?

It is necessary to check the operation of the expansion tank. To do this, you need to pump it with a pump and record its pressure data. If for some reason it does not hold pressure even in the absence of water, it will need to be replaced.

When there is severe frost outside, I add water to the tank every 3-4 days. Does it evaporate so quickly or do we need to look for another reason?

If the pressure on the pressure gauge drops and there is not enough fluid in the system, you need to look for a leak. Perhaps these are small holes, the water from which immediately evaporates, so you do not see the expected puddles. Check all joints and radiators, and then diagnose the expansion tank itself.

The pressure on the pressure gauge drops sharply when I turn on the hot water. Double-circuit boiler. The temperature in the batteries immediately drops. What is the reason?

Such signs indicate the release of water from the system into the central water supply. Check that the supply valve is closed and that it is working properly.

How to bleed an air pocket from a radiator without losing pressure

First you need to determine the location of the air pocket. It is easily localized by the characteristic gurgling sound that accompanies the flow of coolant through the airy area. After this, it would be a good idea to record the initial pressure by reading the pressure gauge. We will focus on this indicator before raising the pressure in the boiler after eliminating the air bubble.

Turn off the boiler or circulation pump (if the latter is not included in the heating device). Pressure equipment generates a force in the heating network, providing circulation, and when etching an air pocket, this force will be unnecessary.

Next, place a bucket or basin under the Mayevsky faucet of the air-filled battery and turn its valve in the direction of the arrow in the desired direction. Air will first flow through the hole in the faucet (with a hiss, like from a deflated balloon), and then water will drip. But do not rush to close the tap - after a small portion of water, air will come out of the battery again. Turn off the valve only after making sure that only water comes out of the tap.

Mayevsky crane

Then read the current pressure value on the pressure gauge (it will be less than the initial one) and open the valve for supplying water to the distribution system from the water supply, monitoring the readings of the pressure gauge. As soon as they approach the starting mark (we wrote it down earlier), close the water supply valve. Now turn on the boiler (pump) and listen to the noise in the radiators. If you hear gurgling or gurgling, do all the above-described manipulations from the very beginning until the gurgling sounds completely disappear as water moves through the pipes and radiators.

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Filter at the heating water inlet to the DHW heat exchanger

Problems with heating hot water sometimes arise and are aggravated due to a clogged filter installed at the heating water inlet to the DHW plate heat exchanger. The filter protects the hot water plate heat exchanger from dirt from the heating circuit.

If the filter is heavily clogged with dirt, then in DHW mode this most often manifests itself as an error: “overheating of the primary supply circuit (NTC2)”. Overheating protection is triggered and the boiler turns off.

For all brands of boilers, the filter is removed differently. But this procedure usually does not present any particular difficulties. No special tool is required. But it will be better to find instructions, a website, pictures or videos on the Internet on this topic. For the first time, you can invite a service specialist and watch how he removes the filter.

Cleaning the DHW filter for double-circuit gas boilers Protherm Gepard and Panther (Panther)

1 — mounting rails, heat exchanger holders; 2 — holder screw; 3 - gasket; 4 - heating water filter at the inlet to the heat exchanger; 5 - DHW heat exchanger of a gas boiler;

To clean the DHW heat exchanger filter you must:

1. Close the taps on the heating water supply and return.
2. Open the drain valve on the boiler, on the right under the pump, and drain the heating water from the boiler.
3. Close the tap at the cold water inlet and disconnect the cold water tube from the boiler. Water will drain from the boiler through the open cold water pipe. Open the hot water taps to completely empty the DHW tract of water.
4. Remove the screws (2) and holder (1) from both sides of the plate heat exchanger.
5. Remove the DHW plate heat exchanger (5). The body of the plate heat exchanger is pressed to the base by mounting rails. After the tires are removed, pull the heat exchanger up and remove it.
6. Remove the gaskets (3).
7. Remove the filter (4) from the hydraulic group.
8. Clean the filter and put everything back.

It is recommended to change the gaskets between the heat exchanger and the base (3) each time during installation. DHW heat exchanger gasket, rubber ring: 22.2x13.5x5 mm. There is a circular recess on the inside. Article number: 0020014166 (10 pieces).

When reinstalling, check that the heat exchanger is positioned correctly - the markings on its side wall should face forward. I recommend taking this moment and descaling the heat exchanger removed from the boiler . How to do this - read the next article on this topic.

More articles on this topic:

⇒ Connecting a layer-by-layer heating boiler to a double-circuit boiler ⇒ Hot water supply for a private country house ⇒ Solar collector - water heater for a house, pool ⇒ Setting up the power adjustment of a gas boiler ⇒ Descaling the DHW heat exchanger of a gas boiler or water heater

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• Heating with a solid fuel boiler with a heat accumulator tank
• Do-it-yourself shallow strip foundation for a house
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How does the operation of a hydraulic accumulator affect pressure?

Problems with the expansion tank that affect the pressure in the heating circuit are very common. Incorrectly calculated volume of the expansion tank is one of the most characteristic prerequisites.

Malfunctions can result from improper installation, low or high pressure in the air chamber of the tank, a damaged membrane - each of the reasons can lead to disruption of coolant circulation in the system.

Expansion tank: device features and volume

If a small volume tank is installed in the heating system, it cannot compensate for the expansion of heating water when heated. At a temperature of 85-95 °C, water expands by approximately 4% and its excess volume exits through the safety relief valve.

In order for the expanzomat to fully perform its compensatory function, its capacity for systems with a gas boiler must be at least 10 percent of the total volume of water in the circuit.

If you install a tank with a larger volume than normal, the pressure fluctuations will be even smaller. Reducing pressure differences has a positive effect on the operation of the system and the service life of heating equipment

Damage to the tank membrane leads to water completely filling its volume and the pressure in the circuit drops. If you fill the volume of the circuit by opening the make-up valve, this will create a new problem - when the coolant heats up, there will be no room for it to expand and the pressure in the system will increase more than normal. The situation can only be corrected by replacing the rubber partition.

The tank should only be installed on the return pipe, in front of the heating boiler. This way the tank will have minimal impact on the operation of the circulation pump, which is installed after the gas boiler. In addition, here the water temperature is lower and the negative impact on the pressure in the system and on the tank membrane will be less.

Setting the pressure in the air chamber

The pressure formed in the air chamber of the expansion chamber can also lead to an increase or decrease in pressure inside the heating system. You can check and pump up the air in the tank only if there is no coolant in the tank.

To do this, you need to shut off access to the common circuit using shut-off valves and drain the water through the drain. Then the pressure in the air chamber is measured and inflated/lowered to the required values.

You can check the pressure in the expansion tank using a car pressure gauge, and pump it up using a car pump.

To set the pressure of the expansion tank in the air chamber, it must be 0.5 bar higher than the expected maximum pressure in the system. After the pressure in the equalizing part of the tank is adjusted, fill the circuit with cold water to the expected pressure value.

Then the air is released from the air chamber until the pressure in the heating circuit and the tank begins to decrease simultaneously - here it is necessary to simultaneously monitor the pressure in the system and in the expansion tank.

In this phase, changes in indicators are little noticeable, so you must be prepared to immediately stop bleeding air from the expansion tank as soon as a simultaneous decrease is detected.

How to check the pressure?

Pressure can be checked using a pressure gauge

Each boiler has a pressure gauge that displays the pressure of the heating system. The initial setup is carried out by a representative of the company with which an agreement was concluded for the installation and maintenance of gas equipment. As the temperature of the coolant increases, the pressure also increases. If gas is added, but the pressure does not increase (the system itself does not maintain the set pressure), then you need to look for the reasons.

The pressure sensors in each boiler are different, as are the recommended parameters. In the instruction manual you can find all the recommendations regarding the normal pressure gauge values.

The control sensor can be displayed on a common display or located inside the structure. In any case, it performs the only function - monitoring the pressure in the system, and if it is low, then heating, or rather the lack of heat, will make itself felt.

Why else can the pressure drop in a double-circuit heating boiler?

Not only the above mentioned points deserve attention. There are other problems:

• If the service life exceeds a sufficient temporary amount, then most likely the boiler automation has simply failed. Because of this, microscopic cracks are possible, which are sometimes difficult to notice with the naked eye.
• When crossing pipelines, the device used may leak.
• The boiler is not suitable for use due to incorrect selection.
• Poor quality installation of the entire heating system.

Preventing the formation of air jams

Preventative measures against the occurrence of air locks are as follows:

1. Pay attention to the correct installation of pipes and connections of heating devices. Many problems are caused precisely by mistakes made at this initial stage.
2. To prevent air locks, proper commissioning of the equipment is necessary, before which it is important to first check all components and connections.
3. Before putting devices into operation, check them for functionality. Using a compressor, you need to apply a pressure level that is ¼ higher than its normal operating value. If it does not weaken within 30 minutes, then everything is in order and the system is ready for operation. If the pressure drops sharply, then leaks are possible, which should be promptly identified and repaired before starting operation.

Watch a video on how to restore normal boiler pressure

Why does the pressure in the boiler drop if there are no leaks?

Of course, in addition to the main problems, there are also indirect ones. For example:

• Formation of so-called air jams. They can be detected due to improper operation of the air release valve - it becomes clogged or the regulation is incorrect.
• Also, due to violation of technical requirements, when coolant systems are filled, low pressure formations are possible.
• Poor sealing also allows air to enter the system.
• Atmospheric suction when connections are found to be loose.

All of these sources are accompanied by characteristic noises and sounds. Therefore, they can be identified quite easily and we can begin to eliminate them. Otherwise, new problems will arise that will be much more difficult to deal with. In addition, not only discomfort may arise for the residents of the structure, but also danger to surrounding people.

How to recognize?

Signs of a large amount of air in the system are:

1. The batteries are too hot at the minimum boiler settings - the air heats up faster than the water.
2. The boiler often goes out - a temperature difference is created at which the automation is triggered.
3. The pressure on the pressure gauge changes abruptly.

Airiness leads to the accumulation of air in certain parts of the radiators, forming air pockets. They cause certain parts of the batteries to remain cooler than others. And if you put your ear to the battery, you can clearly hear gurgling and squelching.

Air lock as a cause of increased pressure

Another possible reason why the pressure itself increases is the presence of air in the heating circuit.

Airing can occur due to:

• when the heating circuit fills with liquid too quickly, the system should be filled slowly, with the air bleed valves open. The valves are open until liquid flows from the highest point of the system;
• Mayevsky's taps are broken, change the taps;
• The impeller of the circulation pump is loose, which may allow air to enter, adjust the impeller.

Operating principle of the boiler

To understand the causes of the breakdown, you need to understand how the boiler works. Double-circuit devices “Ariston”, “Baksi” and other models have several blocks. In the gas unit, ignition and combustion take place, the water unit is responsible for the water supply and pressure in the line. The smoke exhaust unit removes combustion products to the street.

As soon as you start the boiler, the pump is activated, which pumps water into the system. The gas valve opens. The liquid circulates through the tubes of the heat exchanger, and the burner evenly heats its body. Sensors control the heating process. As soon as the temperature reaches the set temperature, the gas supply is turned off and heating stops.

When the temperature begins to decrease, the sensors will send a signal to the control module - the heating cycle will start again.

When the mixer is opened, the flow sensor is activated. It signals the board to switch the three-way valve to DHW heating. When the mixer closes, the valve switches to the heating system. Some models are equipped with a “quick start” mode. Then the valve periodically switches, heating both the first and second heat exchangers.

How to increase the pressure in the boiler depending on the cause of the violation

Here are some troubleshooting tips

1. The most common is leakage. In this case, it is recommended to examine the entire structure as thoroughly as possible and find the place of its origin. If detected, the next step is to cut off the unit from the system. If the pipe is damaged, then you need to replace it: remove the old one and install a new one in its place. It is advisable to carry out the same fraud if the flywheel is damaged. If corrosion occurs at a pipe connection, the area can be sealed.
2. It is always recommended to reproduce preventive measures in advance. This will ensure protection against air locks. Pay attention to the correct connection of the heating structure, as well as all possible valves and components. Always check correct operation before starting work. The test proceeds as follows: apply pressure using the compressor and observe the parameters. If it doesn't weaken within 30 minutes, everything is great.

It is strictly forbidden to carry out repairs on all equipment yourself. It is necessary to call a special service, whose qualified technicians can quickly eliminate all defects and set up the device for further high-quality operation. However, there are situations where urgent repair of the device is required. Then even people who do not have certain knowledge and skills must begin to partially or completely eliminate the breakdown. And of course, the first thing you should do is find out which group of reasons yours belongs to.

What types of pressure are there?

The pressure in a 2-circuit (double-circuit) boiler is divided into the following types:

• static, formed under the influence of gravity, with an increase in height for every meter it becomes higher by 0.1 Bar;
• dynamic, created by pump operation (the greater the pump power, the higher the dynamic pressure) or by increasing temperature;
• working, is obtained by adding two types of pressure - static and dynamic;
• the excess, which is recorded by the pressure gauge, is the difference between the atmospheric and the measured;
• nominal, set in accordance with the physical parameters of the materials from which the gas boiler blocks are made; when operating in this range, the service life declared by the manufacturer is guaranteed;
• maximum, maximum permissible, guaranteeing the exclusion of emergency situations and malfunctions;
• crimping, this pressure is used to test the parts of the unit in production; it can exceed the working pressure by 1.5 times.

Why does the pressure drop in a wall-mounted unit? First, let’s figure out what types there are and how they affect the operation of the equipment.

• Static. The higher the height, the higher the performance. With every meter there is an increase of 0.1 bar.
• Dynamic. Forced operation of the pump creates the rated pressure in a closed system.
• Working. Includes the two options above.
• Excessive. Determined by a pressure gauge as the difference between atmospheric and fixed.
• Nominal. The one indicated by the manufacturer in the documentation for a specific model.
• Maximum. The maximum that is allowed to avoid breakdowns and accidents.
• Crimping. Used in production when testing equipment.

In the heating circuit, indicators are measured in atmospheres

They may vary; It is important that the value does not exceed the permissible maximum and minimum thresholds. A low value is only possible when coolant is pumped into the circuit

In other cases, it should not deviate from the norm.

• Dynamic pressure is the pressure in the coolant that passes through the pipeline and other elements of the heating system;
• Static pressure is the pressure of the coolant on the heating system. Moreover, the coolant is at rest;
• Maximum pressure. The device can operate at this operating pressure. If the arrow rises above the specified level, the equipment stops working.

Each device has its own minimum and maximum pressure values. The minimum pressure can only be when the gas boiler starts operating. As the coolant heats up, the pressure should be equal to normal operating pressure. If this value is underestimated or exceeded, the reasons for the incorrect pressure of the heating device should be considered.

High pressure in the heating system ensures safety and a higher boiling point of the coolant, therefore, the economic effect of the installation increases, and a decrease in pressure leads to problems in the system. Therefore, let’s look at why the pressure in the heating system of a double-circuit boiler drops and how to raise it.

The parameters of the boiler unit are monitored by measuring instruments - pressure gauges, main and additional. If a pressure gauge should be included in instrumentation and control measures, then choose models with electronic sensors.

Factors that affect the pressure inside the circuit:

• The impact of the coolant on the walls of the heating network elements;
• Height of laying pipes, hanging radiators and boiler unit;
• Design of main pipeline sections.

The pressure value for autonomous heating is not standardized. Acceptable values ​​of network parameters are calculated based on the data of a specific object:

• Boiler type, pipe characteristics (diameter, presence of reinforcement, etc.), type and number of radiators;
• Equipment installation location, circuit length;
• Number of floors of the house;
• Parameters and condition of the external water pipeline.

It is important to know! The pressure in the system is determined by the lowest value (usually at the most distant point). In forward and return, the pressure difference should be up to 0.3...0.5 atm to ensure normal circulation of the working fluid

Connecting a single-circuit and double-circuit boiler

Reasons for pressure drop in the circuit:

1. Presence of leaks in the pipeline;
2. Malfunction of the boiler, cracks on the surface of the heat exchanger;
3. Malfunction of the membrane valve responsible for the safety of boiler equipment;

Failure of the expansion tank membrane; Depressurization of the hot water supply circuit.

Preventing problems

Instead of solving a problem, it is better to prevent it in advance. And it's not that difficult to do.

You just need to follow certain rules:

1. Carry out equipment maintenance once a year.
2. Monitor the correct operation of the system.
3. Correct faults in a timely manner.

Before each heating season, you should bleed the air from the radiators. It will only take a few minutes, but it will avoid problems in the future.

In addition, the quality of installation has a great influence . For those who are not particularly versed in heating, it is better to contact specialized organizations. Reworking and correcting mistakes later can be difficult.

Leaks

Gaps are determined visually by pumping water into the pipeline to a predetermined level, and the cycle is stopped. The most susceptible to leaks are the joints of pipes, shut-off valves, radiator connections and the boiler itself.

One of the reasons for the pressure drop is a leak at the junction of the pipe and the radiator

Causes of leaks:

• The presence of corrosion on metal pipes and connections;
• Poor quality pipeline installation;
• Weakening of joints;
• Damage to the pipe due to mechanical impact.

Attention! The network should be inspected several times a season. If there are no puddles on the floor, this does not guarantee that there will be no leaks. A quality inspection includes not only inspection, but also walking around the pipes with a paper towel.

Troubleshooting

If the connection is damaged, replace the fitting or the connection itself. If a leak is detected (by a special scanner) in a pipe behind a decorative partition, wall or under the floor, it is necessary to dismantle the surfaces and make repairs.