How to reduce pressure in a gas boiler
Understand that the system has too much pressure, you can according to manometers. Normally, the indications are 1-2.5 bar. If the arrow of the manometer reaches 3 bar. beat the alarm. If the increase goes constantly, it is urgent to find the cause and reduce the pressure.
Also pay attention to the safety valve: to dump pressure, it will constantly exude water
The case in the expansion tank
This tank can be located separately from the boiler or be part of the structure. Its function is the fence of excess water when heated. Hot liquid expands, it becomes 4% more. This surplus goes to the expansion tank.
The power of the boiler affects the size of the tank. For gas equipment, its volume is 10% of the total number of coolant. For solid fuel. 20%.
Rupture of the membrane. If the part is damaged, the coolant is not restrained by anything, so it completely fills the compensation tank. Then the pressure begins to fall. If you decide to open the crane to add water to the system, the pressure will grow above the norm. There will be a leak in the compounds.
It is necessary to replace the tank or membrane to reduce the pressure.
Pressure below or higher than normal. To achieve normal values (denominations) in a gas boiler will help a machine pump.
- Drain all the water from the system.
- Cross the valves.
- Pump the circuit pump until you make sure that there is no water.
- How to lower the air? Through the nipple on the other side of the supply.
- Download again until the indicators reach the norm specified in the instructions “Ariston”, “Beretta”, “Navien” and other brands.
The location of the tank after the pump provokes hydraulic strokes. The fact is how the pump works. When it starts it, the pressure rises sharply, and then also falls. To avoid such problems, in a closed heating system, install the tank on the reverse pipe. The next breaks the pump in front of the boiler.
Why does the pressure in closed systems increase
Air accumulates in a dual.circuit boiler. Why this happens:
- Incorrect filling with water. The fence is carried out from above, too fast.
- After the repair work, the excess air was not lowered.
- Maevsky taps are broken to describe air.
The impeller of the pump was worn out. Adjust or replace the part.
To reset or reduce pressure, pour the liquid correctly. The fence is carried out from below, slowly, while Maevsky’s cranes are open to pull excess air.
It is important to fill in water correctly and shall bathe air. If after that the pressure is not normalized, it is necessary to drain the system
The node is used to heating the hot water. Its design consists of two isolated tubes. Cold water flows one at a time, on the other already heated. In case of damage to the walls, the appearance of the fistula, the liquid is mixed and fall into the heating part. Then there is an increase in pressure.
If you do not want to engage in the repair and soldering of the heat exchanger, you can replace it. To do this, buy a repair kit and get to work:
The knot is attached by two bolts. Remove them.
The remaining reasons
There are other reasons for such problems:
- Reinforcement is blocked. With the fence, the pressure rises, protective sensors block the equipment. Inspect the taps and valves, unscrew them all the way. Make sure valves performance.
- Zarori filter skeletons. It clogs with garbage, rust, mud. Remove and clean the part. If you have no desire to regularly engage in cleaning, install a magnetic or flushing filter.
- The fuel tap failed. Perhaps his gaskets have worn out, then you can do with a replacement. Otherwise, you will have to change the crane.
- Automation problems. A malfunction of a thermostat or controller. Reason for wear, factory marriage, incorrect connection. Diagnostics, repair are carried out.
Control whether the boiler protection details are working: a pressure gauge, a valve, an air discharge. Carry out radiators and other components from dust, soot, scale. Prevention helps to prevent serious breakdown of gas equipment.
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.
Proper pressure in the expansion tank
The indicator of the free volume of the air region, at an ambient temperature of 18-20 s, is equal to static pressure in the expansion tank of the water sector. In this case, the membrane is in equilibrium, and the pressure of water and air is compensated. For 10 m of the pressure of the heating network, about 1 atm is required.
How to Repressurise a Heating System with an Internal Filling Key
For the normal functioning of the heat supply system, it is necessary to create pressure in the air cavity equal to the passport value of the expansion device.
Many units enter the network with an already created operating parameter in the air sector, they are not required to pump them before installing.
The bulk of the extensors for good work is enough 0.9 atm. This is due to the pressure created by the membrane during use. Its average indicator is 1.2 atm.
If the heat supply system is not equipped according to the traditional scheme, individual calculations are performed before pumping the expansion tank: the volume of network water and the initial pressure of filling the air chamber are calculated.
Norm for different models
Expansion devices are used in the latest heat supply systems and almost replaced open expanders.

In the market of climatic technology, there are enough such offers for brands as Western and domestic manufacturers, they are mainly designed for standard closed and open thermal circuits, can be installed anywhere, unpretentious to the installation and exclude contact of the coolant with air.
The most popular models among Russian buyers are the following modifications of expansion tanks:
- Russia Stout, material synthetic rubber, limit. one.5 atm.
- Germany, Reflex, Material: Synthetic rubber, limit. one.5 atm.
- Italy, CIMM, Material: Synthetic rubber, limit. one.5 atm.
- Russia, unigb, material: synthetic rubber, limit. one.5 atm.
- Italy, Zilmet Cal. Pro 35 on legs, material: synthetic rubber, limit. one.5 atm.
- Russia-Niserlands, Flamco Flexocon R 425 (FL 16416RU), Material Material: Butil rubber, limit. one.5 atm.
- Russia, Jiglex 80 V, membrane material: synthetic rubber, limit. one.5 atm.
- Italy, VRV 50 Aquasystem, membrane material: synthetic rubber, limit. one.5 atm.
Why pressure drops
There may be several reasons for the pressure in systems with compulsory circulation of the coolant:
- Loss of fluid due to violation of sealing the circuit or service devices.
- The heat exchanger due to a long operational period and a rigid, not passed process of water filtration was covered with a growth of salt layering (scale).
- Long work at high temperatures leads to the formation of air in the system. As a result, traffic jams appear that prevent normal fluid circulation, which leads to a decrease in the general pressure of the system.
- The integrity of the heat exchanger was violated.
- The primary sensor failed.
The main part of the breakdowns can be eliminated independently. To do this, you need to correctly determine the reason so that you subsequently not encounter problems of a different nature.
Leak due to impaired sealing
The loss of the coolant is the most common cause of lowering pressure in the boiler and system. To find a problematic place, a surface inspection of the entire contour is carried out. Places with impaired sealing, as a rule, are visible to the naked eye. water drips out of the connection site. There are also cases when a leak is observed on a whole section of the pipe, but in this case you will need a complete replacement of the site or partial with the installation of a passage coupling.
Interesting! It is easier and cheaper to repair a plastic pipeline. It is enough to cut a small damaged area and connect the parts with a coupling.
Elimination of leaks in places of connection of a metal.plastic pipeline have their own nuances. For example, after the promotion of the threaded part, a complete replacement of the FUM tone will be required.
The situation is more complicated if the cause of the leak became a faulty air vent, a drainage valve or a cracked heat exchanger. Perhaps in this situation you will need a complete replacement of details.
If leaks occur in a warm floor system, which is located under a layer of concrete and other finishing material, or on a pipeline walled up in the wall, the process of detecting defective places is almost impossible without removing decorating casing.
The way out of this situation may be the use of thermal imager. It will help to accurately determine the place where the coolant follows.
Opening a crane with hot water
This problem often occurs when using a double-circuit boiler due to its structure. After the opening of the hot water crane is opened, the boiler almost completely switches to the maintenance of the hot water, only partially maintaining heat in the heating circuit.
As a result, the remaining coolant loses heat, and the pressure drops. But this is observed only with prolonged operation, for example, during a bathroom set or a shower adoption. The rest of the time there are no failures.
Important! How to add pressure in a gas boiler? It is enough to block the hot water supply tap.
If after that the pressure does not restore, you need to look for the cause in another place.
Air in the system
The first launch of the system with cold coolant is always accompanied by air accumulation. As a rule, working air vents are able to cope with this problem. However, the device for air removal can fail. The reason for this is the boiled passage hole or distorted float of the device.
To determine the dumping of the system, you need to turn off the loudly working devices and walk along the entire circuit, carefully listening to extraneous sounds. If a characteristic gurgle is heard, with almost 100% confidence it can be argued that air has appeared in the pipeline.
How to increase pressure in a gas boiler if an air cork was found:
- Before starting work, the gas boiler is disconnected.
- It is most convenient to steal air through the crane of Maevsky. It is located from the end of the radiator.
- For air release, use a special key-butter, which comes with heating batteries. In its absence, you can use a slotted screwdriver.
After removing air traffic jams, to raise the pressure, you need to fill the circuit with a new portion of the coolant. During filling, necessarily includes a circulation pump. As soon as the pressure gauge shows the necessary values, the air is re.discharged until it completely removes.
Important! If this operation has not helped, it is necessary to remove the coolant from the system and replace the damaged air carrier.
The expansion tank is faulty
The main purpose of the expansion tank is the hydraulic compensation of the system with the physical expansion of water due to its heating by a heating boiler. The design is a tank divided in two rubber membrane. The upper chamber is filled at the plant with a special gas, the lower one is a compensator. It is there that the excesses of the expanded liquid enter.
If the cause is its malfunction, first of all you need to pay attention to the nipple. Worn gum leads to air passing and reducing pressure.
- First you need to try to download air into the upper half of the tank using a pump.
- If the hiss continues, one thing remains. to completely replace the nipple.
Комментарии и мнения владельцев 159
may not be tight. the tank passes through the collapse, remove to remove
Xs, remove the boiler once again and turn off the heating in the winter is not the most successful option while I am following its work

Things for half an hour, drain the water only from the boiler. Unscrew the nut by 17 remove the tank up, do not need to remove the boiler
How to deal with Low Pressure in a Combi-Boiler
You need to properly pump up the expander. On mine, it was and simple podness did not help for a long time.one. Close the heating circuit 2 taps so that the system stands with water.2. Dry all the water from the boiler. Inside the boiler there should be a drain crane.3. Pour the bachech up to 1.5-1.7.4. Fill the boiler to 1.5 bar.5. Open the cranes of the heating circuit and you will be happy.
In my boiler, there seems to be not a crane for draining water, I only have a crane on the return
In general, all this boltka should stop when a stable street air temperature is established and the boiler begins to work constant.e. time intervals between v. and open. will be the same during the whole time of his work. www.Stavan.ru/katalog/Inf x/reflex%20instr%20ng.pdf you did not notice the connection: the warmer on the street the lower the pressure drop, and when it is colder the other way around? The pressure will be all equal, but it will be less noticeable with a large expander. First of all, membrane tanks are used to compensate for the temperature expansion of the liquid, and already in the second some compensation for its pressure. Of course banal, but there may be a leak of the coolant, usually manifests itself when Min T or Max T reaches.
PS in general measured the pressure in the extensor today, it was 1.I pumped it up to 1.6, tucked the boiler with water. I will follow.It turns out I still need to put a separate extensor as previously wrote liters for 40-50. And with old what to do? Somehow drown out it and bring it out with a metal.plastic to a new expander?
Maxim, you don’t need another extensioner, believe me, you don’t lose anything. Drain water from the boiler to zero and from the expander up to 1 bar, no more. And the boiler will be normal.
I opened the crane under the boiler today, a liter-two merged from it. Measured the pressure in the extensor, there is 1.0 atm was, I decided to download it because opinions diverge how much to swing. I took the pump that is clamped and pumped up with his hand. Then in the boiler I gained pressure up to 1.5. So everything had to be done ?
You have a problem not in the boiler, but in the system. If you want to make sure, do what I wrote yesterday, cut off the boiler from the system with cranes and see for yourself.And pull the pressure in the expander back up to 1 bar plowing after salting water from the boiler. Then tape the water back.
If there was a hole somewhere in the system, then the pressure would fall slowly, and so I have 10 days, 1.3 and then I see that the display blinks on 0.8 type Small pressure
It’s so difficult for you to check what is the problem, in the boiler or in the system, as I wrote yesterday? Just believe someone else’s experience. Result and will be the starting point. Without it, Budesh will continue to guess and give food for further disputes on the site.
If there was a hole somewhere in the system, then the pressure would fall slowly, and so I have 10 days, 1.3 and then I see that the display blinks on 0.8 type Small pressure
But in general there may be a failure in the electronic pressure sensor.
PS in general measured the pressure in the extensor today, it was 1.I pumped it up to 1.6, tucked the boiler with water. I will follow.It turns out I still need to put a separate extensor as previously wrote liters for 40-50. And with old what to do? Somehow drown out it and bring it out with a metal.plastic to a new expander?
I took expansion bass 20 percent of the total media in the system, I have 90 liters in the system, a 25 liter tank, the pressure in the tank pumped 1.5.
The pressure in the expansion tank should be 0.9.Before pumping water.And you will be happy.
In the exterator, it was originally 1.0, tomorrow I will return again to 1.0, but what will change then, it turns out nothing will change and the pressure will also fall
Look, somewhere pulls.How old is the boiler.
See all the connections, while turn off the boiler so that the batteries and all.what was tied to the boiler was cold, otherwise you will not see.
Look for a leak. Recently, there was the same problem, my head was rackfall until the wife of the tweezers gave that the corner in the boiler room is wet, the connection was over him
My Westen Pulsar did not always lose pressure. The taps of the radiators changed, and the cause of the defect of the secondary heat exchanger.
The boiler is not like that, but the problem was the same. I lowered the expansion tank, pumped it up to 1.2 on the disconnected and lowered system, filled it and now everything works fine and the pressure does not drop.
I didn’t hold a little hot water in the bathtub a few drops per day, I missed a day every two weeks when I added a month, I changed the pressure for two years fine.
I have the same boiler. Last year I launched the system, from November to February everything was fine until they lived, kept a temperature of 15 ° C (air). When they moved added somewhere to 25 ° C and after three weeks it also began that you also. There were no leaks, I have an additional RB for 12l. In both tanks, pressure 1-1.2ATM (so the gazmiers advised me, and I keep the pressure in the system 1.5-1.6Atm. This year has not yet been nothing. he did not feed the system.And by the way, these same gazmiers advised me to put an automatic recharge system, this is a crane-sensor that turns on with a certain drop in pressure. And as I understand it, this advice was not there, maybe the jamb of this boiler.
Rules for using equipment. operating instructions Protherm cheetah
The boiler turns on and turns off using the main circuit breaker located on the boiler control panel.
After turning on, its current state will be displayed on the boiler display:
If the boiler is in standby mode
(heating and hot water does not occur), then the display displays the current value of the water pressure in the heating system, and the light part of the display is depicted
In the heating system below the value of 0.5 bar on the display, the symbol will flash
Together with the current pressure in the heating system. When the pressure falls in the heating system below the value of 0.3 bar on the display, the symbol will begin to flash
pressure in the heating system 0.0 bar. In this case, it is necessary to raise pressure in the system by adding water to the system.As soon as the pressure in the heating system reaches 0.5 bar, the pressure value will stop flashing, and the symbol
the current value of pressure in the heating system. In this case, it is necessary to reduce water pressure in the heating system by draining from the system. As soon as the pressure in the heating system drops below the level of 2.4 bar, the parameters of the current condition of the boiler will be displayed on the display.
Gepard boiler can work in various modes:
Mode once, a symbol will display on the display
pressure in the heating system. In this mode, the boiler heats only heating, heating hot water is disconnected.
Two times, the display value in the heating system together with the symbol will appear on the display

carries out only to heating hot water, heating heating is disconnected.
Mode 3 times, the “OFF” symbol will be displayed on the display, as well as the current pressure value in the heating system. When choosing this function, the hot water and heating modes are not active, but all the protective functions of the boiler remain included.
Click the “” or “-” button, the symbol will blink on the display
Using the “” or “-” buttons, select the desired value of hot water temperature (settings 38. 60 ° C in a step in one degree).
Rules for using equipment. operating instructions Protherm cheetah
For the impeccable operation of the boiler, it is necessary that the heating system maintain a certain pressure of the coolant (at least 1 bar, which corresponds to a hydrostatic height of 10.meter water column). It is recommended to maintain pressure in the range from 1.2 to 2 bars.
Water feeding into a heating system (but only in small quantities) is carried out using a firmware valve installed on the boiler.
When feeding the heating system, the following requirements must be observed:
Be sure to above the pressure of the water in the heating system
exclusively in a chilled state (the temperature of the coolant in the boiler should not exceed 30 ° C),
water in a cauldron in a cold state (up to 30 ° C) should be in the range from 1 to 2 bar.
tank and, if necessary, adjust it.
The drain valve is intended primarily to reduce water pressure in the boiler in case of repair. Drain the water from the boiler through the drain valve can only be partially.
To fill and drain the coolant from the heating and boiler system, additional valves should be installed in the heating system.
Drain and filling the heating system, as well as other accompanying
Operations (air removal, setting up an expansion tank) are not the subject of warranty service of the boiler.
In the case of the threat of freezing of the coolant in the boiler and the hot water supply system, it is necessary to take measures to fully eliminate it.
Note: The drain valve is located on the right side of the boiler near the pump.
Before filling the heating system, check the pressure in the expansion tank. The initial pressure in the expansion tank should be 0.2 bars higher than the static height of the water column in the heating system.
Fill the heating system with water. The content of the filling should be 0.2. 0.3 bares higher than the pressure in the expansion tank. Water pressure when filling the heating system is controlled by the manometer. The final pressure value is checked in the cold state of the heating system and after removing air from the system.
Nipple for regulating the pressure of the expansion tank is on the right side.
What pressure in the boiler is considered normal
Characterize the heat supply system with several indicators:
- Statistical. depends on the height of the pipes of the heating network. It grows with an increase in the height of the object, for each meter, statistical pressure increases by 0.1 atm. For example, statistical pressure in the three.story building will be 3×3 = 9 m = 0.9 bar = 0.9 atm.
- Dynamic, provided by an electric pump of heat supply. For example, usually the pump provides indicator 1.2 atm.
- The operating pressure of the boiler is the amount of statistical and dynamic: 0.9 1.3 = 2.3 bar = 2.3 atm.
- Excessive, set by a manometer, is a difference between the atmosphere and pressure in the water eyeliner line. It depends on evaporation in the boiler surfaces of heating. If the heat supply source has a steam cooker, it can be used to heat the heating circuit.
- Nominal. corresponds to the estimated operation of the boiler unit and the circuit of heat supply.
- The maximum pressure should be for the safe operation of heat engineering equipment.
- Pressing. hydraulic testing with increased pressure of the heating circuit to the connection density, usually 1.5 from the working indicator, more accurately indicated by the manufacturer of the unit.
In the heat power industry, the pressure in the heating boiler is measured in atmospheres and is determined by the manometer or primary sensor. To make the equipment work properly so that the value does not exceed the permitted maximum/minimum threshold. For a standard cottage, the norm for a double.circuit boiler from 1.2 to 2.5 bar.
How to solve the problem of pressure falling
If you have never had to restore boiler equipment with your own hands before, you should not deal with independent repair. Without knowing the schemes and principles of the operation of the units, you can make mistakes and disable the entire system.
To repair the equipment, you need to carry out a number of complex events. First of all, it is important to determine what the pressure drops in the boiler in the dual-circuit installation.
In devices with forced circulation, fluid leaks lead to problems. To determine the place of leaks, you need to conduct a comprehensive inspection of the joints.
Often, incorrectly performed installation leads to leaks. To prevent such consequences, it is better to entrust the task of installing a specialist in advance.
During the initial examination, it is problematic to find a leakage place. When a puddle appears under the pipeline, you need to start the repair as quickly as possible. Otherwise, the breakdown will lead to deplorable consequences. In most cases, the repair involves the replacement of old pipes that were subjected to corrosion processes.
In the presence of a complex wiring, the process of searching for a leak site can cause a number of difficulties. With unstable pressure and the absence of the opportunity to find the cause of the breakdown, you will need to call a specialist who involves special devices to quickly and efficiently determine the error.
Before performing the repair, you need to disconnect the radiators and the boiler from the system and find the damaged area. In case of pipe deformation, it should be replaced by a new. If the leak is formed at the junction of the pipes, repeated sealing is performed. A special tape or sealant is used as a sealing composition.
If the problem is related to malfunctions in the expansion tank, it means that the inappropriate volume was chosen or the membrane was damaged. Repair will require repeated calculations or replacement of the tank.
When dropping pressure after the first launch, you should not worry about the failure of the heating system. This is a normal reaction associated with the fact that a large amount of air is present in the circuit. With normal operation of the equipment, the bubbles will leave the pipeline, and the characteristics of the circuit will be stabilized. To get bubbles faster, you will need to use a manual mechanism for air lingering.
If there is damage to the heat exchanger due to intensive operation and wear, it will be difficult to find the source of the problem without specialized equipment.
To prevent numerous problems in the operation of the heating system, including reduction of pressure, it is important to carry out comprehensive prevention and comply with a number of rules of use. It is worth monitoring the correctness of connecting the pipeline and heating elements, since many errors are made at the installation stage.
To avoid the formation of air traffic jams in the heating circuit, it is important to correctly fix the working nodes, make sure of the valves and connections, and also diagnose. The pressure is supplied using a compressor by ¼ more standard value. If after 30 minutes the indicators do not fall, this will indicate that the error is eliminated and you can proceed to the operation of the boiler in the same mode. If sharp pressure surges are noticed, you will need a re.check of the system for the presence of leaks.