Why does the pressure in the gas boiler drop or grow: the causes of the pressure of the pressure method of preventing problems
Work to ensure the proper functioning of heating equipment does not end on its installation. Service requires a certain level of knowledge from the owner and constant monitoring the state of the system. It is important to understand why the pressure in the gas boiler drops or grows, which is why the equipment functions with changes.
The article presented by us describes in detail all the reasons for the instability of pressure in the system of preparation of the coolant and hot water. We will talk about how to eliminate problems and maintain indicators in the normal range. Our recommendations will help to cope with planning breakdowns and prevent failures in work.
What normal pressure in the gas boiler?
The pressure rate in the boiler makes it possible to reduce heat loss to the minimum, and the coolant is in the same temperature as exists in the boiler. Specifically answer the question: “What pressure should be in the gas boiler?” it is forbidden. The following criteria affect this value:
The device and capabilities of the coil, where the resource is heated, directly affect optimal pressure. Modern gas boilers are equipped with high.quality heat exchangers that withstand up to 3 atmospheres. For solid fuel units, it is recommended to use the 2 atm indicator., not higher.
The values indicated in the data sheet indicate the maximum threshold that boilers are capable of, and “force” them to work in this mode is not desirable. This is due to the fact that when heated inside the system, an increase in pressure occurs. The average value between the lower and upper thresholds can ensure the full functioning of the boiler and radiators.
To find out the optimal value of the working pressure, it is necessary to take into account the parameters of the manufacturer and the boiler, and other heating devices. Typically, their indicator varies within 0.5. 1.5 atmospheres. If the value in the autonomous heating system is within this framework, it will be enough for normal performance.
Note! There are people who believe that high pressure in the pipeline contributes to the high productivity of the unit. Although the studies have shown that the difference when working with an pressure of 1 atmosphere and 2 atm. In a private house is very insignificant. But the wear of the pipeline nodes increases much.
In addition, in the process of heating the resource, the pressure in the gas boiler can fluctuate slightly, and in the settings with a lower level of value, this will not affect the work of other parts of the highway too much. The functioning in high pressure mode occurs with additional loads and needs to be installed by the expansion tank and the safety valve.
Air pressure in the expansion tank
The air or nitrogen pressure indicator in the expansion tank for various gas boilers will not be the same, it all depends on the type of equipment and structural features. Standards are indicated by the manufacturer in the product passport.
Typically, the pressure in the new damper capacity is 1.5 atm. But such a setting may not be suitable for a specific heating system. Factory parameters are easy to drop. For these purposes, in the housing of the expansion tank there is a special fitting (some manufacturers are spool for pumping), through which air pressure is adjusted.
Nippel is located from the air chamber of the cylinder. With it, you can lower excess pressure or, conversely, pump up the tank
For the normal functioning of a gas boiler, it is necessary that in the membrane tank, the pressure is less than 0.2 atm than in the system itself. Otherwise the heated water that increased in volume will not be able to enter the container.
In small houses and apartments for closed heating systems, pressure in the expansion hydraulic tank is usually acceptable in the range of 0.8-1.0 bar (atm). But not less than 0.7 bar, because many gas boilers are protected and the device simply does not turn on.
Check the level of pressure of the tank annually. If pressure surges in the heating system are noticed, it means that air has come out of the damper capacity and it must be pumped up.
Pressure in the open heating system
Unlike a closed thermal circuit, a properly built open heating system does not require balancing over the years of operation. it is self.regulatory. The work of the boiler and static pressure provide constant circulation of water in the system.

The density of the heated water following the supply of the riser below the density of the chilled coolant. Hot water seeks to take the highest point of the circuit, and chilled. to be at its very bottom.
The pressure necessary for water circulation is achieved by pressure in the supply riser or an increasing pump
The pressure developed by the water column in the supply riser contributes to the circulation of the coolant and compensates for the resistance available in the contour pipeline. It causes friction of water on the inner surface of the pipes, as well as local resistances (turns and branches of the pipeline, boiler, reinforcement).
By the way, high.diameter pipes are used to assemble an open heating system to reduce friction.
To understand how to increase the pressure in the open heating system, you must first understand the principle of achieving circulation pressure in the thermal circuit.
- RC. circulation pressure;
- H is a vertical distance between the centers of the boiler and the lower heating radiator;
- RG. the density of the heated coolant;
- RO. density of chilled coolant.
Static pressure will be higher if the distance between the central axes of the boiler and the battery closest to it will be as significant as possible. Accordingly, the intensity of the circulation of the coolant will be higher.
To achieve the maximum possible pressure in the heating circuit, it is necessary to lower the boiler as low as possible. into the basement.
The closer the radiator to the boiler, the better it warms up. Regulators allow distributing heat between all radiators of the heating system
The second reason for the fall pressure in the open heating system is associated with its self.regulation. When the temperature of the heating of the coolant changes, the intensity of its flow rate changes. Increasing the heating of water for the thermal circuit on cold winter days, the owners sharply reduce its density.
However, when passing through heating radiators, water gives the heat of the room atmosphere, while its density increases. And according to the formula presented above, the high difference in densities of hot and chilled water helps to increase circulation pressure.
The stronger the coolant warms up and the colder in the premises of the house, the higher the pressure in the system. However, after the atmosphere of the premises warms up and the heat transfer of the radiators decreases, the pressure in the open system will drop. the difference between the temperature of the water at the supply and on the return will be reduced.
Balancing of a double.circuit open heat system
Gravitational heating systems are performed with one or more contours. In this case, the length of each looped pipeline horizontally should not exceed 30 m.
But to achieve optimal pressure and pressure in an open system with a natural movement of the coolant, it is better to perform pipelines even shorter. less than 25 m. Then it will be easier to fight hydraulic resistance to water. In the circuit with several rings, in addition to limiting the length, you should observe the condition for heating radiators. the number of sections in all rings should be approximately equal.
Lack of pressure in an open double-circuit heat system occurs due to errors of design or pollution of the pipeline
Balance of horizontal rings included in the vertical circuit is required at the stage of designing the heating system. If the hydraulic resistance of a ring is higher than that of the rest-static pressure in it will not be enough and the pressure will virtually stop.
To maintain the necessary pressure in the double.circuit heating system, it is necessary to reduce the cross section of the pipes on the approach to the radiators. You can also install valves in front of radiators that perform thermoregulation (manual or automatic).

You can balance an open double.circuit system: you can:
- Manually. We start the heating system, follow the atmosphere temperature of each heated room. Where it is higher. we fasten the valve, where below. promote. To configure thermal balance, you will have to perform temperature measurements and adjust the valves several times;
- Using thermostatic valves. Balancing occurs almost independently, you just need to set the desired temperature in each room on the handles of the valves. Each such device will control the supply of the coolant into the radiator itself, increasing or decreasing the supply of the coolant.
It is especially important that the total hydraulic resistance of the heating system (all rings in the contours) is not higher than the value of the circulation pressure. Otherwise, heating the coolant and attempts to balancing the system will not improve circulation.
Circulation pump for an open heat system
It happens that measures to balancing the heating circuit of the gravitational system do not give the effect. Not all causes of low pressure are solved by setting. the choice of incorrect diameter of the pipes cannot be fixed without a complete reconstruction of the contour.
Then, in order to increase pressure and improve the movement of water without a significant alteration of heating, a circulation pump or an increasing pumping device is mounted in the system. The only thing the installation will require is the transfer of an expansion tank or its replacement for a membrane expanomate (closed tank).
Air congestion
Their occurrence in the system is caused by various causes. The most common are:
The main feature of the air cork is the interruption of heat supply at some point of the system after.
It is not difficult to remove the case. The air is tinted through the descent valve (it is included in the safety of the boiler) or the Maevsky crane (arranged on radiators).
What is the need for an expansion tank
The expansion tank in the boiler serves as an additional reservoir and the compensator of the expansion that occurs in the process of heating. In order to avoid a strong increase in pressure, and so that the fuse valve does not work, installed in the boilers for three atmospheres, you need this expansion tank.
This tank is also needed to compensate for the pressure itself, when the system cools, so that it remains in a certain spectrum suitable for the measured operation of the boiler. So that she does not fall into the reddish zone and the boiler is not blocked. The excess heated liquid gets specifically there, and after cooling, the pressure again comes to the measured level, and the liquid through the pipes is again in the system.
Verification of pressure
Unlike old models of heating equipment, modern gas boilers are equipped with devices that allow you to accurately determine the pressure in the boiler. It can be mechanical or electronic manometers:
- Mechanical devices have a built.in spring. During movement, the coolant has a load on the spring mechanism, which drives other parts that contribute to the movement of the arrow along the manifold of the pressure gauge. This is how the pressure in the system is determined.
- The action of electronic models is somewhat complicated, since operation is carried out using an electrocontact mechanism. These devices are more accurate and durable.
In order to receive the most accurate readings, pressure control devices in the system are installed on the supply line for the trimmer. after the boiler, together with the security group and after the circulation pump.
How to raise water pressure in a gas boiler:
- The initial flooding of the coolant is carried out with joint air sipping. It is necessary to bring the indicators, focusing on the pressure gauge, up to 1.2 bar.
- After which the circulation pump is launched.
- The gas boiler is turned on, which leads to heating the coolant, its expansion, and, as a result, an increase in pressure. Before starting, you need to carefully study the instructions where the working pressure should be indicated. Focusing on the information received, you need to align the indicators in the system.
Attention! The subsequent operation of the gas boiler is controlled by periodic reconciliation of hydraulic pressure on the pressure gauge.
If a gas boiler with an electronic pressure gauge is operated in the house, when the pressure drops, information with an error code will appear on the device display. If the measures to eliminate the malfunctions are not taken, over time the boiler will automatically turn off.

Ferroli Italian gas boiler: instructions, devices of the device, as well as the main errors and plan for operating these products
Italian gas boilers Ferroli are the products of one of the strongest European manufacturers.
Equipment manufactured by this company demonstrates high quality and stability of work, all components and parts of the gas boilers of Ferroli are collected on the basis of advanced technologies and fully meet the most stringent technical requirements.
Each unit is equipped with an extensive system of self.diagnosis, consisting of a network of sensors, which are located on all responsible nodes and details of the boiler.
In case of any malfunction or exit of the unit from a given mode, the self-diagnosis system immediately responds by notifying the user using the alphanumerous code on the boiler display.
The main malfunctions of gas boilers Ferroli
The design of Ferroli boilers has a well.thought.out and high.quality study of all components and details.
However, any system has weak places, and gas boilers are no exception.
How to repressurise your boiler
The working conditions of some parts of the units are very complex, temperature loads contribute to the occurrence of the phenomenon of fatal fatal and other materials.
According to experts, the most common malfunctions can be attributed:
- The boiler does not turn on. There may be different reasons and ways to eliminate them, one of the most common malfunctions.
- Pressure drops or grows. This is a serious problem, which leads either to the leakage of the coolant, which causes overheating and blocking the boiler, or to exceeding the pressure and blocking. It is especially dangerous to increase the pressure from which the parts of the unit can burst.
- Fan or circulation pump. Loss of both functions means the inability of the system. the inability to withdraw smoke causes sharp overheating and blocking, and the absence of fluid movement has the same consequences, only detected by other sensors.
- Electronic controls of control. The cause of these problems is most often an unstable power voltage or the absence of high.quality grounding. The electronics of the boiler is very sensitive to any changes in the operating mode. When drops or jumps appear, she begins to give out a continuous series of errors that are not repeated when restarting. Often there is an accumulation of a static charge on the case, which is transmitted through the mass to the control board and electrode of ionization, which causes the appearance of error A02 (the system sees the flame when it is not). The solution to the problem is the complete disconnection of the boiler from the power system for some time and the restoration (or creation) of high.quality grounding.
Ferroli boiler “37 F” error solution
In addition to these, there are a lot of problems with the combustion mode:
All these problems are associated with the deterioration of gas supply due to clogging of the nozzles, failing of the thermocouple or the fuel valve coil.
All the main errors and decryption and decision
Consider the basic errors of Ferroli gas boilers and options for their elimination:
The code | Decoding | Ways to solve the problem |
A01 | Lack of flame (unsuccessful attempt to ignit) | Check the presence of gas in the highway, open the gas supply crane, |
A02 | False presence of flame (voltage was detected on the ionization electrode with a shine of the burner) | Check the condition of the grounding circuit or the presence of condensation drops on control board |
A03 | Overheating of the boiler | Rinse the heat exchanger, check the condition of the circulation pump |
A06 | Lack of flame after a rod cycle | Check the gas supply system, clean the nozzles of a gas burner |
A08 | Refusal of the temperature sensor of the coolant | Replace the element |
A09 | The refusal of the gas valve | Check performance, replace the element |
F04 | Overheating of smoke gases thermostat | Clean the chimney, check the fan performance |
F05 | Failure system failure, fan shut | Replace the fan |
F08 | Overheating of the primary heat exchanger | Rinse the heat exchanger, if necessary, replace it |
F10 | Cliff or KZ temperature sensor OV | Restore contact or replace the sensor |
F11 | Cliff or KZ sensor of the temperature of the hot water | Restore contact or replace the sensor |
F14 | Direct line of the heating circuit line | Restore contact or replace the sensor |
F34 | The supply voltage fell to 180 in | Check the fishing line for the trimmer, install a stabilizer or uninterrupted fence |
F37 | Drop in pressure s | Detect an OV leak and eliminate it |
F40 | Excessive pressure s | Check the condition of the expansion tank |
F47 | Cliff or short circuit of the pressure relay | Restore performance or replace the relay |
F50 | Problems in the work of management fees | Replace the control board |
Ferroli boilers are divided into critical (a) and non.critical (f). Those that with Litera A lead to an independent blocking of the boiler, and with Litera F. do not bring.
Operating instructions. how to start correctly
The operation of Ferroli boilers is not distinguished by any specific actions and procedures.
The owner requires only the organization of periodic maintenance, cleaning the body and the insides of the boiler, in the proper order of the nozzles of the burner.
The procedure for launching the boiler resembles a method of ignition of other gas units.
A feature is the need to stand a pause between starting attempts, during which the D3 or D4 code appears on the display (50 or 30 seconds).
The first code occurs after the appearance of a critical error and blocking the unit.
Tips and recommendations for pressure adjustment in a gas boiler
Be sure before raising pressure in gas boilers, you should make sure that the system is sealed. For this, all heating devices, pipes, fittings, circular pumps are inspected.

Experts also advise to carefully monitor the upper limit of pressure in the system. it should not exceed three atmospheres.
Adding pressure in the tank is possible with ordinary air using a car pump with a pressure gauge.
note! To prevent the formation of air s, it is necessary to correctly select the boiler model for the premises, coordinating possible areas for heating and the power of the unit.
Any private house should be heated and equipped with hot water. In modern construction, gas boilers are used for this. For their normal functioning, optimal pressure is necessary, which for a number of reasons can fall, which leads to a stop of the boiler. A competent owner should know how to raise it, or contact specialists.