The pressure in the heating system of a private house drops

It can be quite annoying, particularly in the winter, when the pressure in your home’s heating system decreases. Your home’s circulatory system is similar to your heating system, and a loss of pressure in the latter is similar to a blood vessel leak. This decrease in pressure may result in inefficient heating, which could be uncomfortable and possibly even cause damage to your property.

Your heating system’s pressure may drop for a number of reasons. A common offender is a leak in the system somewhere. Similar to a tire puncture, a leak in your heating system can let water seep out and lower pressure. These leaks can happen in radiators, valves, pipes, and other components of the system.

Air trapped in the system could be another cause of a drop in pressure. Air displaces water and lowers the total pressure when it builds up. This air may accumulate over time as a result of insufficient radiator air bleeding, or it may enter the system during installation or maintenance operations.

Furthermore, a malfunctioning pressure relief valve may occasionally be the source of pressure variations. Although the purpose of this valve is to remove excess pressure from the system to avoid damage, a malfunction could result in pressure drops. This valve needs to be maintained and checked frequently to make sure it’s operating properly.

Regardless of the reason, it’s imperative to handle a drop in pressure in your heating system as soon as possible to preserve optimal performance and stop more problems. In the sections that follow, we’ll go over typical techniques for identifying and resolving pressure drops in your heating system, enabling you to maintain a warm and cozy house all year long.

For what reasons does the pressure drop in the heating system of a private house?

Plan for heating a house

Russian stoves, which are used for both cooking and heating, are extremely uncommon in contemporary private homes. With the use of gas equipment, closed-type heating has developed quickly in recent years. Regretfully, a pressure drop can occasionally happen in a private home’s heating system, even with flawless installation.

Even with the new system, similar issues may arise, despite what would seem to be an impossibility. However, as it happens, there are a number of causes for this. To comprehend them, you must be familiar with the water system’s device.

How the water heating system works a private house?

The boiler is the primary heating apparatus. It is essential for the coolant to flow through the pipes and the release of thermal energy that occurs during fuel combustion.

The fuel you can use for a boiler will depend on its type.

Electricity has been used as a heat source in the development and successful application of heating schemes. However, despite being the safest, this method is costly.

Note: You must install an expansion tank before installing any heating equipment in front of the boiler. It is employed to maintain the coolant’s pressure equilibrium.

The work of the expansion tank

There is a membrane on the pressure stabilization device that shares the working space with air. The purpose of the heating system’s expansion tank is to collect extra coolant that forms as a result of heating system expansion and replenish it back into the system during cooling.

The water expands when heated, increasing pressure in all pipes and heating equipment as well as the volume that flows into the tank. In this instance, the membrane is stretched and the air volume reduces, resulting in compression. The system’s pressure rises in this situation.

Coolant temperature drops cause a drop in system volume and pressure, which forces the water that was previously accepted into the tank to be forced out of it by compressed air.

Air heating in the room

Radiators are made of pipes in a variety of ways.

Each room has radiators installed, which provide the room’s heating. They can be made of steel, aluminum, cast iron, or bimetallic materials, depending on the material used. Gimettall batteries look great and have great heat transfer.

An extensive pipe system governs the flow of water into heating devices. to guarantee the heating system’s working pressure and the coolant’s uniform and quick movement. Use a circulation pump. There are systems where water moves due to gravity as well.

Manometers, locking reinforcement, and drains for drainage valves are crucial components.

The heating system in your home may need repair if the pressure in it decreases for a number of reasons. Low pressure can potentially harm the system and cause inefficient heating. A malfunctioning pressure relief valve, air trapped in the system, or leaks in the pipes are common causes. It’s imperative to take care of these problems right away in order to keep your house cozy and energy-efficient. Pressure drops can be avoided and year-round operation of your heating system can be guaranteed with routine maintenance and inspections.

Why does the pressure in the heating system change?

There are several reasons why the heating system experiences miscellaneous pressure:

  • Coarler leak.
  • The system has air.
  • The use of aluminum radiators.

Coarler leak

It frequently originates from the expansion tank, joints, or batteries. Water leaks from areas where rust is present, or where corrosion is present.

The expansion tank’s ruptured membrane prevents you from discarding the leakage option. In this instance, pressing the nipple at the top of the tank will allow you to check for leaks. Coolant leakage occurs when air and water are let out. The only element that should be normal is air. If every joint on the highway was examined and there were no leaks found, there may be another cause for the dropping pressure issue.

The system has air

Air traffic congestion within the battery

There are various reasons why air traffic jams occur:

  • Violation of technical requirements when filling the system with a coolant.
  • Poor water preparation before filling the system, that is, there is no unit for forced removal of air dissolved in the coolant.
  • Farms of the coolant, when the air leaks occur during loose connections.
  • Incorrect operation of devices for lowering air – when the valve is closed or not adjusted.

Noise is produced by air plugs in heating systems. This phenomenon is detrimental to heating systems in addition to being unpleasant for occupants of individual homes or apartment buildings.

More serious issues arise when air is present in pipes and heating apparatuses:

  • During noise, the pipeline vibrates, which weakens threaded joints and destroys welds.
  • The system is poorly fainted, which does not allow it to adjust it and can lead to the cessation of the circulation of the coolant in separate batteries or risers. In this case, it is quite possible to defrost the system. And if the movement of the coolant does not stop completely, then the efficiency of the heating circuit decreases, and fuel consumption increases.

The load that develops when air forms and enters the pump impeller could cause damage to it.

There are multiple ways to stop air from getting into the system.

How to avoid air entering the heating system?

  • It is necessary to correctly put into operation an mounted heating scheme. This should be done by a specialist. Before starting, you need to inspect both the system as a whole and each connection, taps and valves, assessing their performance. Very often, when examined, the shut -off valve in the boiler remains unnoticed, although it can also pass water.
  • It is necessary to test the system of pressure. To do this, the compressor needs to supply pressure 25% more than the working pressure of the coolant. If it does not have a strong decrease for 20 minutes, then the system is mounted well and can be put into operation. But if the pressure fell, then a leak occurred, which must be detected and eliminated. The loss of water may indicate a characteristic whistle. It can also be determined if the joints are coated with soap solution. The release of bubbles will occur in the places of passing the coolant.
  • The filling of the system is carried out with cold water and gradually. Before starting, you need to open all the taps for the water descent. If possible, then unscrew the plugs in the batteries and release air from the system. If the design allows, then open the valve for the lifting of the circuit.

The heating system doesn’t require forced air discharge if the network pump is launched last and everything is done correctly. Maevsky cranes mounted on each battery and an autoclap will allow its negligible amount to descend. Coolant must be added to the working pressure in the heating system after the air has been drawn out.

There are times when air gets trapped in the pipes while the system is operating. The following steps need to be taken in order to get rid of it:

  • Determine the possible location of the air traffic jam. If it is available, the battery or pipe becomes cold.
  • Find a point a little further and higher in the heating during the course of the water – where there is an air valve or a chill. Through it it is necessary to lower the air, turning on the system of the system.

The use of aluminum batteries

Installing radiators made of aluminum

A thin film forms on the surface of aluminum when water comes into contact with it. In this instance, a contractible hydrogen molecule is released as a byproduct. And as a result, there is less pressure. However, this phenomenon is limited to new radiators and does not happen all the time. It eventually comes to an end, and the issue is resolved on its own.

Its growth may coincide with a drop in the pipeline pressure of the single- or multi-story building.

There are various reasons why the boiler’s pressure may be rising:

  • Damage to the boiler recharge crane. It can sore it or just grind a rubber seal. After detecting the defect, it is necessary to replace the gaskets.
  • The heat exchanger flows. For verification, you need to dismantle the boiler and test with air. If a breakdown is detected, the part must be replaced by a new.

You must disconnect the boiler from the outlet and turn off the cold water while performing boiler repairs.


In order to eliminate the causes of pressure increases or decreases in the housing heating system, you must first accurately design the system and, during installation, precisely follow the planned sequence of actions without deviation. It is important to call experts right away if you see that the heating system’s pressure is rising in order to avoid equipment failure.

Why does the pressure fall in the heating system

Despite no leaks, the two-story building’s heating system’s pressure continuously drops before units and lower. What might be the reason?

Unfortunately, no miracles exist. You cannot disobey the laws of physics. A leak occurs when the pressure decreases. You simply fail to notice her.

Together, let’s search for a "weak place." The three primary parts of the fuel-energy heating system (there are others) are boiler equipment, pipelines, and heating devices. Let’s examine it in more detail:

  1. Heating devices can be sectional (batteries) or whole (convectors). Hermetization of batteries is much more often disturbed. We carefully examine the joints of the sections, we carry out in search of moisture at the bottom of each connection with your hand, blotter, napkin. If the leak is detected, you will have to reproach the battery, having previously removed. Gaskets (just in case at all the joints that we are promoting, not only on a drunk) should be replaced.
  2. Pipelines, as a rule, flow in places of joints. Marriage is much less common when the leak forms in the pipe itself. If you have communication hidden from the eye (warm floors, passages through the walls, wiring in the floor and walls), it is no wonder not to notice the leakage. The search for such defects is difficult.
  • The equipment of the boiler room may well be a source of leaks. List of possible problems:
  • The expansion tank is incorrectly selected in volume. There may be pressure surges that can lead to periodic operation of the safety emergency valve, the discharge of the coolant. If the valve does not have direct discharge into the sewer, the leak can be easily detected.
  • In the expansion tank, the tightness of the membrane can be impaired, “poison” nipple. It is necessary to measure the air pressure, if necessary, pump up in accordance with the instructions. And trace whether the fall is observed.
  • If the heating system is fueled from the water supply, the check valve or shut -off crane is likely. And only if the pressure in the water supply (not necessarily constantly) is lower than in the heating system. The reverse leak is visually determined.
  • The problem can also be hidden in the boiler itself. In the heat exchanger, the presence of micro. Its occurrence is able to provoke a hydraulic system, overheating, high wear, the formation of a scale inside the exchanger, mechanical damage. To a certain temperature, the defect can not show itself in any way. Когда теплоноситель нагревается, микротрещина раскрывается и жидкость вытекает, тут же испаряясь. Diagnosing micro -hardness is quite difficult. If the coolant (water) has a high carbonate stiffness, you should look for the dreams, traces of salts.
    Copper heat exchanger can be sealed, aluminum and stainless steel is restored and this can only be done in factory conditions. Crack in cast iron cannot be eliminated. Cast iron heat exchangers, it happens that they "sniff" at the site of the sections. In the photo the heat exchanger with a "good leak". But the hole for the time being can be inconspicuous
  • A drop in pressure, not directly related to the equipment:
  • If the system after the end of the installation is filled not specially prepared by the coolant, and with water, a fairly large amount of gases is dissolved in it. They are gradually released from the liquid and exit through automatic fabricers or are pulled manually. The system is replenished again and the process is repeated, already in a smaller volume. The complete adaptation of the coolant composition and the removal of dissolved air from it occurs within two to four weeks. If the pressure drops after a month, the reason lies in something else.
  • If there are a significant number of copper and aluminum parts in the heating system (for example, the copper strapping of the boiler, bronze fittings, aluminum radiators) water decomposes into oxygen and hydrogen. Gases go through the fabric. However, this process is very long, the pressure can fall to the pressure to a unit for months, or even years.
  • Regretfully, it may even prove challenging for experts to identify a trustworthy cause for the pressure decrease and the leak location. Compressed air is frequently pumped into the system in the hopes of hearing a hiss or whistle. There are traces left behind after the coolant dries, so in certain situations staining it a noticeable color helps.

    A decrease in pressure to one like yours can seriously harm apparatus. particularly if it occurs fast. Look for leaks or get in touch with experts. Additionally, avoid following unofficial advice "from the Internet" and add radiator sealant or mustard to the water to avoid turning off a heating boiler.

    The reasons for the drop in pressure in the heating system of the double -circuit boiler. Types of problems and their elimination

    Employing boilers with closed circulation, or double-circuit, is advised for heating networks in homes and apartments. The working fluid pressure in the circuit can be raised thanks to this design.

    Elevated pressure within the heating system ensures security and raises the coolant’s boiling point, thereby increasing the installation’s economic impact. Conversely, lowering pressure causes issues within the system. As a result, we will examine the reasons behind the double-circuit boiler’s heating system pressure drop and offer solutions for raising it.

    Manometers, both primary and secondary, are the measuring instruments used to regulate the boiler unit’s parameters. Models with electronic sensors are selected if the manometer is to be incorporated into the instrumentation.

    Factors influencing the circuit’s internal pressure include:

    • Exposure to the coolant on the walls of the elements of the heating network;
    • The height of the pipe laying, suspension of radiators and a boiler unit;
    • The design of the trunk sections of the pipeline.

    There is no normalization of the pressure value for autonomous heating. Based on the information of a specific object, the network parameters’ allowable values are determined:

    • The type of boiler, pipes characteristics (diameter, the presence of reinforcement, etc.), type and number of radiators;
    • The location of the equipment, the length of the circuit;
    • The number of storeys of the house;
    • Parameters and condition of the external water conduit.

    It’s critical to understand! The lowest indicator (usually at the farthest point) determines the system pressure. For normal working fluid circulation in a straight line and return, the pressure differential should be as high as 0.3 to 0.5 atm.

    Connecting a boiler with a single and double circuit

    The following are the causes of the circuit’s pressure drop:

    1. The presence of leaks in the pipeline;
    2. Violation of the boiler, cracks on the surface of the heat exchanger;
    3. Violation of the membrane valve responsible for the safety of boiler equipment;
    4. The failure of the membrane of the expansion tank;
    5. Depressurization of the hot water supply circuit.

    By visually identifying the gaps and pumping water into the pipeline to a predetermined level, the cycle is broken. The joints between pipes, shut-off valves, radiator attachments, and the boiler itself are the most prone to leaks.

    The leak at the pipe-radiator junction is one of the causes of the pressure drop.

    • The presence of corrosion on metal pipes and compounds;
    • Low -quality installation of the pipeline;
    • Weakening joints;
    • Pipe damage during mechanical exposure.

    Take note! A few network inspections should be done each season. The absence of puddles on the floor does not imply that there are no leaks. A high-quality check involves not only visual inspection but also using a paper towel to circumvent the pipes.

    Elimination of the problem

    The fitting or the connection itself needs to be replaced if it is damaged. Surface disassembly and repair are required if the flow is discovered (using a specialized scanner) in the pipe beneath a wall, decorative partition, or beneath the flooring.

    Expansion tank and its pumping

    One possible source of circuit pressure in a closed system is an expansion tank that has failed.

    • Frequent systems of the system. If there is a need to additionally introduce the coolant into the system, at least once a week, without visible leaks, then the problem is the incorrect operation of the expansion tank;
    • Scattering of manometer readings for different operating modes of the system. A sharp drop in the pressure of the coolant in the system using hot water supply also indicates malfunctions in the Republic of Belarus.

    The expansion tank’s internal pressure

    You must pump the tank and examine whether the pressure inside it matches the pressure in the heating system in order to confirm the performance.

    The pumping actions in order:

    1. Block locking taps (straight and reverse water supply);
    2. Open the fitting, drain the water until the magnitude of the pressure in the boiler becomes zero;
    3. Remove the testimonies on the extension tank in the position of the "Open" fitting. The presence of condensate on the Republic of Belarus should not be observed;
    4. Superfire air in the Republic of Belarus before the liquid does not stop flowing from the fitting. Let the water drain from the tank completely;
    5. Release air;
    6. Repeat the procedure, holding the pressure in the Republic of Belarus at the level of 1.1 … 1.3 bar;
    7. Open locking reinforcement;
    8. Run the coolant into the network. Set pressure level 1 … 1.1 bar.

    If you don’t have an RB specific pump, you can ride a standard bicycle.

    Take note! The majority of manufacturers list the air compartment pressure in the equipment passport. This makes the process of choosing a boiler expansion tank a lot easier.

    If there is no expansion tank

    After the boiler, the expansion tank is the second most crucial component of the home heating system. The volume of water varies with temperature. Since the volume within the circuit is constant, an extensor tank—which serves as a compensator—is also connected to the circuit to allow for the allocation of excess coolant. Thus, RB serves as an object-guide that averts emergency scenarios such as pipe depressurization and elevated pressure.

    It is not highly advised to use boiler equipment without an expansion tank.

    The pressure of RB must match the system’s volume, t.To, for stable operation. Coolant volume should be raised when pipes are used in place of radiators. However, an excessively large RB will prevent the circuit’s working pressure from being maintained.

    An expansion tank that can hold 120 liters of coolant in the circuit (usually a two-room apartment) is standard. The safety valve will be used to release water when heating and expanding the volume if the tank is too small. Due to its volume, the boiler cannot be started when it is turned off or the fluid temperature drops, which means there won’t be enough pressure. In these situations, more networking is required.

    Competent calculation of the heating system

    Making the expansion tank selection in a private home is your responsibility. Pipe freezing is likely to occur if the volume is not high enough and the system is not started.

    An assortment of expansion tanks

    It is recommended to check the installed equipment twice a year: once during the cold season (when heating is more intense) and again right after installation.

    Reasons for Pressure Drop Solutions
    1. Air in the system Bleed air from radiators
    2. Water leaks Locate and fix leaks
    3. Faulty pressure relief valve Replace or repair valve

    It’s critical to take quick action to fix a dropping heating system pressure in your private home in order to prevent further problems. If low pressure is ignored, it can cause system damage, uneven heating throughout the house, and decreased heating efficiency.

    Air that has become trapped in the system is one of the main causes of pressure loss. Pressure decreases can result from air pockets obstructing the water’s natural circulation. Bleeding the radiators and making sure the system is properly ventilated can help resolve this problem.

    Over time, pressure loss can also be brought on by system leaks. These leaks may appear in the boiler itself or in fittings, pipes, or valves. Frequent maintenance and inspections can assist in finding and repairing these leaks before they become serious issues.

    Furthermore, changes in external factors like temperature variations or water expansion may cause fluctuations in pressure. While small variations are typical, large and frequent drops in pressure call for further examination to rule out any underlying problems.

    Regularly checking the pressure gauge on your heating system is crucial. Learn the ideal pressure range for your particular system, which is usually between 1 and 1.5 bar, and take appropriate action if the pressure drops or rises outside of this range.

    In conclusion, the longevity and effective operation of the heating system in your private home depend on maintaining the right pressure. You can guarantee a cozy and reliable heating system all year long by quickly addressing pressure drops, whether by bleeding radiators, repairing leaks, or keeping an eye out for variations.

    Video on the topic

    Why does the pressure fall in the heating system

    The main reasons for the pressure fall in individual heating systems

    The pressure in the heating system drops. We analyze the causes and eliminate problems.

    What type of heating you would like to have in your home?
    Share to friends
    Anna Vasilieva
    Rate author
    Add a comment