Instructions for installing a pump in the heating system of a private house. Water pump for heating: consider water pumps for heating a private house. Installation diagram of a heating pump.

Many people are faced with the need to independently install a circulation pump. There are usually two reasons - either the boiler does not initially have a pump (and it is irrational to change pipes to products with a larger cross-section), or its power is not enough to uniformly heat all the rooms through which the heating circuit is laid.

For example, if a heated extension (garage or other) was erected after the residential building was built and inhabited. How to properly install a pump that circulates the coolant through the heating system, what to consider - many questions arise during the installation process. This article will give detailed answers to the most common ones.

Selecting a pump installation location

Opinions on this issue are completely opposite. Most are confident that the only correct solution is at the inlet of the domestic boiler, on the so-called “return” line. Although supporters of installing a circulation pump at the outlet of the unit argue that the location of the device at the supply makes heating more efficient. Who is right?

From the point of view of the laws of physics (there is such a discipline as hydraulics), this is not fundamental. In any case, the impeller will “pump” the coolant through the pump, that is, ensure the movement of liquid along a closed circuit. But taking into account the peculiarities of the operation of a domestic boiler, its “reaction” to emergency situations arising in the heating system, the circulation pump should be installed only on the “return”, that is, at the inlet of the unit.

Why? The circulation pump is designed to work with liquid media. In the event of an emergency, the coolant may boil, and steam will form at the boiler outlet, which will enter the heating system. The pump will cease to perform its function, since the impeller is not able to pump gaseous media. As a result, circulation in the circuit will stop, which will lead to an even greater increase in temperature in the heat exchanger. Next (if the automation did not work) - the boiler explodes. But if the pump is installed on the return line, then the risk that steam will “get” to it is reduced to zero.

Conclusion - from the point of view of safe operation of boiler equipment, the circulation pump should be installed only on the “return”, that is, on the pipe connected to the inlet pipe of the unit. Even if the heat generator is the latest model, with the most advanced automation, it is inappropriate to rely only on it. What if he refuses? After all, no one will argue that none of the technical means is 100% reliable.

Features and rules for installing the pump

Heating system pipes are laid according to various schemes. For a circulation pump, it makes no difference whether it is installed on a vertical “thread” or a horizontal one. The main thing is that the product is connected correctly. This is where a typical mistake is often made, which is that the inlet and outlet pipes are swapped. How not to confuse them if they are visually indistinguishable - neither by thread nor by cross-section?

There is an arrow on the pump body. It is clearly visible. It shows the direction of movement of the coolant. Consequently, its pointed tip points to the outlet pipe. This means that the circulation pump must be installed in the heating system so that this side faces the boiler. In addition, the device’s passport (and it is necessarily attached) shows the recommended installation diagram.

Regardless of the specifics of the pump installation (spatial orientation), a mandatory condition is the horizontal position of the rotor. This is also indicated in the passport.

When installing a circulation pump, in most cases a bypass is installed. Its purpose is clear - to ensure the movement of coolant along the circuit, even if the pump fails or needs to be temporarily dismantled. For example, for service. And here opinions differ. Some believe that it is correct to install the pump on a pipe, while others believe that it is correct to install it on a bypass. What to follow?

Since after the pump stops operating, circulation will be provided either by the device installed in the boiler, or by the temperature difference (in non-volatile systems), it is necessary to create the most favorable conditions for the movement of the coolant. Therefore, when the device is turned off, it must go through the pipe directly, bypassing the bypass. The pictures explain everything.

This installation option (on a bypass) is implemented for heating systems that are installed under non-volatile boilers, that is, as “gravity-flowing”.

With this installation of the pump, it is possible to organize automatic switching of the circulation from bypass to direct “thread”. It is enough just to install a check valve (“petal valve”) instead of a ball valve mounted on a pipe.

When the pump stops, the pressure in the system will drop, this valve element will open, and the fluid movement will continue, but directly. Moreover, the time of such switching is minimal, so such a modification of the circuit will not affect the heating efficiency and operating mode of the boiler.

A good solution for owners of private buildings. After all, this is a rare case when there is definitely someone in the house. Even a person who has retired does not sit constantly “within four walls”, but is absent on various matters. It is precisely at this time that problems with energy supply may arise.

This scheme should not be interpreted unambiguously, although there are opinions that it is incorrect. Some boilers initially do not have their own pump. Therefore, where to install the purchased one does not matter. In a circuit that is designed for forced circulation, there will be no “gravity flow” of the coolant by definition. If only because of the lack of the required slopes of the “threads”. This means that the pump can be installed directly on the pipe, since installing a bypass in this case makes no sense. But definitely - between the boiler and the expansion tank.

The position of the cleaning filter relative to the circulation pump (another controversial issue) depends on the characteristics of the heating circuit:

• If the system is open, then in front of the device, but on the bypass.
• In cases with solid fuel boilers - in front of the valve (3-way).
• In pressure systems, the “sump trap” is installed before the bypass.

This work should be done in the so-called “off-season”. But if there is a need to carry out the installation during the heating season, the boiler needs to be “turned off” and wait until the temperature of the coolant drops - these are basic things that do not need additional comments.

• If it is necessary to install a bypass, it is better to assemble it separately, installing all the fittings and the circulation pump. All that remains is to make an insert into the pipe.
• The next stage is bleeding the air while simultaneously monitoring the system to detect leaks.

After this, you can safely switch the circuit to work with a pump.

Circulation pumps are divided into 2 groups, according to the specific location of the rotor - “wet” and “dry”. What is the difference? Without going into the specifics of engineering solutions, it is enough to just note the pros and cons of each modification.

With a “dry” rotor. Higher efficiency. But there are also disadvantages - increased “noise”, the need for regular maintenance (primarily lubrication of seals) and special requirements for operating conditions. Such circulation pumps must be installed in separate, absolutely clean rooms. The explanation is simple - the slightest dust leads to a decrease in their efficiency or breakdown.

With a “wet” rotor. As a rule, these pumps are installed more often. The fact is that all modern household heating boilers are initially equipped with such a device (located under the casing of the unit), and the newly installed one serves only as an additional element that ensures better coolant circulation. For example, when choosing the wrong heat generator model, when increasing the length of the heating circuit, when installing radiators not provided for in the primary circuit.

The disadvantage of such a pump is low efficiency. But taking into account that it is not the only one in the system, this drawback is leveled out, since it does not particularly affect the heating efficiency. An additional advantage is that no maintenance is required. Such pumps function properly until their service life is completely exhausted, provided that the rules for their installation are followed.

Installing a circulation pump in homes with an individual heating system ensures uniform and high-quality heat distribution throughout all rooms of the house.

Closed heating systems require forced circulation of hot water. This function is performed by circulation pumps, which consist of a metal motor or rotor attached to a housing, most often made of stainless steel. The release of the coolant is ensured by the impeller. It is located on the rotor shaft. This entire system is driven by an electric motor.

Circulation pump

Also in the design of the described installations there are the following elements:

• shut-off and check valves;
• flow part (usually made of bronze alloy);
• thermostat (it protects the pump from overheating and ensures economical operation of the device);
• work timer;
• connector (male).

When installed in a heating system, the pump draws in water and then delivers it into the pipeline due to centrifugal force. This force is generated when the impeller produces rotational movements. The circulation pump will work effectively only if the pressure it creates can easily cope with the resistance (hydraulic) of various components of the heating system (radiator, pipeline itself).

Various circulation units can be installed in the heating system of a private house. They are divided into two large groups. The circulation pump can be “dry” or “wet”. When installing devices of the first type with your own hands, you should take into account that their motor is separated from the working part by sealing rings. They are made from stainless steel. During the startup of the installation, the process of movement of these rings begins, which leads to sealing of the connection with a water (very thin) film. The latter is located between the seals.

Circulation pump unit

High-quality sealing in this case is ensured due to the fact that the pressure in the external atmosphere and in the heating system itself is characterized by different indicators. A “dry” pump makes quite loud sounds when operating. In this regard, its installation is always carried out in a specially soundproofed separate room of a private house. The efficiency of such a circulation unit is at the level of 80%.

There are three types of “dry” devices for connecting to the heating system: horizontal, vertical, block. The electric motor in units of the first type is placed horizontally. The discharge pipe is attached to them on the body of the device, and the suction pipe is attached to the shaft (on its front side). In vertical installations, the pipes are on the same axis. And the engine in this case is located vertically. In block circulation units, heated water exits radially and enters the system in the axial direction.

Caring for a “dry” unit is objectively difficult. Its elements must be regularly lubricated with a special compound. If this is not done, the mechanical seals will quickly fail, causing the pump to stop. In addition, in a private home, “dry” devices should be placed in rooms where there is no dust. Its turbulence during equipment operation often causes depressurization of the pump.

In “wet” units, the lubricant function is performed by the coolant itself. The impeller and rotor of such installations are immersed in water. “Wet” devices are much less noisy and easier to install with your own hands. And their maintenance is simpler compared to “dry” pumps.

The body of a “wet” installation is usually made of brass or bronze. Between the stator and the rotor there is always a special stainless steel separator. It's called a glass. It is necessary to provide the required tightness to the engine (more precisely, its elements under electrical voltage). It is “wet” units that are most often installed in a heating system in a private home.

They do a good job of heating relatively small areas. Such devices are not suitable for large objects, since their productivity usually does not exceed 50%. The low efficiency of “wet” installations is due to the impossibility of high-quality sealing of the cup placed between the stator and the rotor.

The key indicator that determines the efficiency of the circulation pump is its power. For a household heating system, there is no need to try to purchase the highest-power installation. It will only make a loud noise and waste electricity.

Mounted circulation pump

• hot water pressure indicator;
• pipe section;
• productivity and throughput of the heating boiler;
• coolant temperature.

Hot water consumption is determined simply. It is equal to the power indicator of the heating unit. If, for example, you have a 20 kW unit, no more than 20 liters of water will be consumed per hour. The pressure of the circulation unit for the heating system for every 10 m of pipes is about 50 cm. The longer the pipeline, the more powerful the pump you need to purchase. Here you should immediately pay attention to the thickness of the pipe products. The resistance to water movement in the system will be stronger if you install pipes with a small cross-section.

In pipelines with a diameter of half an inch, the coolant flow rate is 5.7 liters per minute at the generally accepted (1.5 m/s) speed of water movement, with a diameter of 1 inch - 30 liters. But for pipes with a cross-section of 2 inches, the flow rate will already be at the level of 170 liters. Always select the diameter of the pipes in such a way that you do not have to overpay extra money for energy resources.

The flow rate of the pump itself is determined by the following ratio: N/t2-t1. In this formula, t1 refers to the temperature of the water in the return pipes (usually it is 65–70 °C), and t2 is the temperature provided by the heating unit (at least 90 °C). And the letter N denotes the boiler power (this value is in the equipment passport). The pump pressure is set according to the standards accepted in our country and Europe. It is believed that 1 kW of power of a circulation unit is quite enough for high-quality heating of 1 square meter of a private home.

Circulation pumps are installed in two ways. The first connection diagram for the unit is two-pipe. This connection method is described by a high temperature difference in the system and variable coolant flow. The second scheme is one-pipe. In this case, the temperature difference in will be insignificant, and the media consumption will be constant.

Installed circulation pump

Connect the pump yourself according to the instructions that come with the unit. It also indicates the installation procedure for the functional reinforcement chain. Before installing the pump, be sure to drain all water from the system. Often there is a need to clean it. During the operation of the heating boiler, a lot of debris accumulates on the internal surfaces of the pipes, which worsens the technical performance of the system.

Experts advise placing the circulation unit in front of the boiler - on the return line. This is done in order to eliminate the risk of boiling of an open type heating system due to the vacuum that is created when installing the supply pump. In addition, if you install a circulation unit on the return line, its trouble-free operation will be significantly increased due to the fact that it will operate at lower temperatures.

The pump installation procedure itself looks like this:

1. Make a bypass (in professional slang - bypass) in the area where the pump will be located. The bypass diameter is always taken to be slightly smaller compared to the cross-section of the main pipe.
2. Mount (strictly horizontally) the shaft of the pumping device, and place the terminal box on top.
3. Place valves (ball valves) on both sides of the pump.
4. Install the filter. It is not recommended to operate the equipment without this device.
5. Place an automatic (or manual) release valve above the bypass line. This device will allow you to clean air pockets that regularly form in the system.

Next, valves (shut-off) are installed at the inlet-outlet section of the circulation unit. For an open heating system, an expansion tank is additionally required (not installed in closed complexes). The final stage of installation work is the treatment of all connection points of various elements of the system with a good sealant.

The uniform distribution of heat in a house with an autonomous heating system is determined by the model of pumping device used. This equipment ensures the forced movement of a warm medium through pipes and radiators.

To determine which heating pump connection diagram will be optimal for independent implementation, many details must be taken into account. In this article, we will consider in detail possible connection schemes and analyze the connection rules in detail.

We will also pay attention to the subtleties of choosing a location for installation, supplementing the material with thematic photos and diagrams.

Just a couple of decades ago, in the private sector, houses were equipped with gravity-type heating. A wood stove or gas boiler was used as a heat source. There was only one area of ​​application left for large circulation devices - centralized heating networks.

Today, manufacturers of heating equipment offer smaller units that have the following advantages:

1. The speed of movement of the coolant has increased. The heat generated by the boiler quickly enters the radiators. Due to this, the process of warming up the premises was significantly accelerated.
2. The higher the movement speed, the higher the pipe capacity. This means that an identical volume of heat can be delivered to rooms using a pipe with a smaller diameter.
3. Water heating schemes have undergone significant changes. The highway can be laid with the slightest slope. Also, the complexity and length of the line can be anything. The basic rule is the rational choice of a heating pump based on the required power.
4. With the help of a household circulation device, it became possible to organize heated floors in the house, as well as an efficient closed-type heating system.
5. It became possible to hide the entire heating communication line, passing through the rooms, which does not always go well with the design of the room. Options for laying pipes behind suspended ceilings, in walls or under floor coverings are quite common.

The disadvantages of pumping systems include the dependence of operation on the supply of electricity and its consumption by the pumping apparatus during the heating season.

The leading company Grundfos, engaged in the development of heating equipment, has released innovative models of Alpfa2 circulation pumps, capable of changing performance based on the needs of the heating system, which allows saving on electricity consumption

Therefore, if the area is often deprived of power supply, it would be advisable to install a device to provide uninterrupted power. The second drawback is not critical and can be eliminated by the power and model of the circulation pump.

Selecting the location for inserting the device into the system

The installation of the circulation pump is supposed to be in the area immediately after the heat generator, not reaching the first branch line. The chosen pipeline does not matter - it can be either a supply or a return line.

Where can I put the pump?

Modern models of household heating units, made of high-quality materials, can withstand temperatures of a maximum of 100 °C. However, most systems are not designed for higher heating of the coolant.

The coolant temperature in the personal heating network rarely even reaches 70 °C. The boiler also does not heat the water above 90 degrees

Its performance will be equally effective on both the supply and return branches.

And that's why:

1. The density of water when heated to 50 °C is 987 kg/m3, and at 70 degrees – 977.9 kg/m3;
2. The heating unit is capable of generating hydrostatic pressure of 4-6 m of water column and pumping almost 1 ton of coolant per hour.

From this we can conclude: the insignificant difference of 9 kg/m 3 between the statistical pressure of the moving coolant and the return does not affect the quality of space heating.

Are there exceptions to the rules?

As an exception, inexpensive ones with a direct combustion type can serve. Their device does not provide automation, so at the moment of overheating, the coolant begins to boil.

Installation of collector wiring in a heating system using a solid fuel boiler is considered the most effective. However, this type of heating of a private house is one of the most difficult to perform.

Problems begin to arise if the electric pump installed in the supply line begins to fill with hot water and steam.

The coolant penetrates through the housing with the impeller and the following occurs:

1. Due to the action of gases on the impeller of the pumping device, the efficiency of the unit decreases. As a result, the coolant circulation rate coefficient is significantly reduced.
2. An insufficient amount of cold liquid enters the expansion tank located near the suction pipe. The overheating of the mechanism increases and even more steam is formed.
3. A large amount of steam entering the impeller completely stops the movement of warm water along the line. Due to the increase in pressure, the trigger occurs. Steam is released directly into the boiler room. An emergency situation is being created.
4. If the firewood is not extinguished at this moment, the valve will not be able to cope with the load and an explosion will occur.

In practice, no more than 5 minutes pass from the initial moment of overheating to the activation of the safety valve. If you install the circulation mechanism on the return branch, then the period of time during which steam enters the device increases to 30 minutes. This gap will be enough to eliminate the heat supply.

In inexpensive heat generators made of low-quality metal, the response pressure of the safety valve corresponds to 2 Bar. In high-quality solid fuel boilers - this indicator is 3 Bar

From this we can conclude that it is impractical and even dangerous to install a circulation device on the supply line. Pumps for solid fuel heat generators are best installed in the return pipeline. However, this requirement does not apply to automated systems.

Heating with a group of separate lines

If the heating system is divided into two separate lines, heating the right and left sides of the cottage or several floors, it would be more practical to install an individual pump for each of the branches.

When installing a separate device for the heating line on the second floor, it becomes possible to save money by adjusting the required operating mode. Due to the fact that heat has the property of rising, it will always be warmer on the second floor. This will reduce the coolant circulation rate.

The pump is inserted in the same way - in the area located immediately after the heat generator before the first branch in this heating circuit. Typically, when installing two units in a two-story house, fuel consumption for servicing the upper floor will be significantly less.

Schemes for different types of systems

Initially, it is necessary to determine the insertion area of ​​the circulation device. With its help, the process of active movement of liquid is carried out - the flow passes through the boiler and is forcibly directed to the heating radiators.

To locate a household pump, it is necessary to determine the most convenient area so that it can be easily serviced. On the supply side, it is installed after the boiler shut-off valve.

In order to carry out maintenance and control the functioning of equipment, it is necessary to install shut-off valves. Thus, any element of the heating system can be removed without completely dismantling the line

On the return pipeline, the pump is placed after the expansion tank in front of the heat generator.

Due to the presence of various mechanical impurities in the water, for example, sand, problems may arise in the operation of the pumping mechanism. Particles contribute to jamming of the impeller, and in the worst case, stopping the motor. Therefore, you will need to install a strainer strainer directly in front of the unit.

Separately, it is worth mentioning the issue of an open-type heating system. It is capable of operating in two modes - with forced and gravity coolant circulation.

The second option is more suitable for areas with frequent power outages. This is much more economical than purchasing an uninterruptible power supply or generator. In this case, the unit with shut-off valves must be installed on, and a tap must be inserted into the direct line.

In stores you can find ready-made units with a bypass. In place of the flow tap, there is a spring-loaded non-return valve. This solution is not recommended - the valve produces a resistance force of 0.1 Bar, which is considered a large indicator for a gravity-type circulation system.

It is better to use a reed valve instead. However, its installation is carried out strictly horizontally.

Solid fuel pump and boiler

The pump is connected to the system with a solid fuel unit on the return line. In this case, the pumping device is connected to the boiler circuit with a bypass and a three-way mixing valve. In addition, the latter can be equipped with a servo drive and an overhead temperature sensor.

The connection diagram for a solid fuel boiler is based on two important elements that allow it to function effectively in the heating system of a private home. These include: a safety group and a mixing unit based on a three-way mixing valve

Due to the fact that the maximum performance of heating equipment is used to its fullest extent only during the cold period, it is possible to install a heat accumulator (TA). It is able to absorb excess heat and then, on demand, release it to the heating circuit.

This battery is made in the form of a tank and is lined with thermal insulation material. On one side of the device there are two pipes intended for connecting it, and two on the other - for connecting to the radiator line.

The heat accumulator has two circuits: small and large. The first one receives energy from the boiler, the second one supplies coolant to the heating system as needed.

As the liquid passes through the boiler, which operates at maximum, the coolant in the heat accumulator warms up over time to 90-110 degrees. In a large circuit, the insertion of another circulation device is required.

Depending on the degree of cooling of the liquid in the heating system, the required amount of heat from the storage device will enter through the valve.

Pump installation diagram

To perform its functions, household circulation equipment, regardless of the manufacturer, must be connected to a pipe or shut-off and control valves.

Fastening is done using union nuts. This fixation option will allow you to remove it if necessary, for example, for inspection or repair.

When choosing a circulation pump model, you need to pay attention to its ability to function in different positions. Vertical placement of the device reduces its power by up to 30%

Correct installation of all elements of the heating system ensures uniform heating of the entire line.

When installing the circulation pump, the following rules must be observed:

1. It is allowed to install the device on any section of the pipe. The pipeline can be located horizontally, vertically or inclined. However, the rotor axis must be in a horizontal position. Therefore, installation “head down” or, conversely, up is impossible.
2. It is worth paying close attention to the location of the plastic box where the power supply contacts are located - they will be on top of the body. Otherwise, they may be flooded with water in an emergency. To do this, you will need to unscrew the fastening screws on the casing and turn it in the required direction.
3. Observe the direction of flow. It is indicated by an arrow on the device body.

With all its weight, the pump presses on the body of the ball valves located nearby. This should be taken into account when choosing fittings. High-quality parts are equipped with a powerful body, which during operation will not become cracked from daily stress.

Installation of additional equipment

Regardless of the type of heating circuit used, where one boiler serves as the heat producer, it will be sufficient to install a single pumping device.

If the design of the system is more complex, it is possible to use additional devices that provide forced circulation of liquid.

This becomes necessary in the following cases:

• when heating a house, more than one boiler unit is involved;
• if there is a buffer capacity in the piping scheme;
• the heating system diverges into several branches, for example, servicing an indirect boiler, several floors, etc.;
• when using a hydraulic separator;
• when the pipeline length is more than 80 meters;
• when organizing water movement in floor heating circuits.

To perform the correct piping of several boilers operating on different fuels, there is a need to install backup pumps.

For scheme c, the installation of an additional circulation pump is also required. In this case, the main line consists of two circuits - heating and boiler.

A more complex heating scheme is implemented in large houses with 2-3 floors. Due to the branching of the system into several lines, 2 or more pumps are used to pump the coolant.

They are responsible for supplying coolant to each floor to various heating devices.

Regardless of the number of pumping devices, they are installed on the bypass. In the off-season, the heating system can operate without a pump, which is shut off using ball valves

If you plan to install heated floors in the house, then it is advisable to install two circulation pumps.

In the complex, the pumping and mixing unit is responsible for preparing the coolant, i.e. maintaining the temperature at 30-40 °C.

In order for the power of the main pumping device to be sufficient to overcome the local hydraulic resistance of the floor contours, the length of the line should not be more than 50 m. Otherwise, the heating of the floors will become uneven and, accordingly, the rooms

In some cases, the installation of pumping units is not required at all. Many models of wall-mounted electric and gas generators already have built-in circulation devices.

Rules for connecting to power supply

The circulation pump is powered. The connection is standard. It is recommended to install a separate power supply line with a surge protector.

To connect, you need to prepare 3 wires - phase, neutral and ground.

You can choose any of the connection methods:

• via device;
• connection to the network together with an uninterruptible power supply;
• power supply to the pump from the boiler automation system;
• with thermostat regulation.

Many people wonder why complicate things, because connecting the pump can be done by connecting a plug to a wire. This is how the pumping device is plugged into a regular outlet.

A circuit with a differential machine is used for so-called wet groups. A heating system constructed in this way ensures a high degree of safety for wiring, equipment and people.

The first option is not difficult to assemble yourself. It is necessary to install an 8 A differential circuit breaker. The wire cross-section is selected based on the device rating.

In the standard scheme, the power supply is carried out to the upper sockets - they are marked with odd numbers, the load - to the lower ones (even numbers). Both phase and neutral will be connected to the machine, so the connectors for the latter are designated by the letter N.

To automate the process of stopping the circulation of the coolant when cooling to a certain temperature, an electrical circuit is used to connect the pump and thermostat. The second is mounted in the supply line.

At the moment when the water temperature drops to the specified value, the device disconnects the electrical supply circuit.

In order for the thermostat to turn off the circulation process at the right time, it is installed on a metal section of the pipeline line. Due to poor heat conductivity of polymers, installation on a plastic pipe will result in incorrect operation of the device

There are no difficulties in supplying electricity through an uninterruptible power supply; it has special connectors for this. A heat generator is also connected to them when there is a need to provide electricity.

If you choose the method of connecting the pump to the boiler control panel or automation, you will need good knowledge of the power supply system or the help of a professional.

Conclusions and useful video on the topic

Rules for installing heating equipment in the video:

The video explains the features of a two-pipe heating system and demonstrates different installation schemes for devices:

Features of connecting a heat accumulator to a heating system in the video:

If you know all the connection rules, there will be no difficulties with installing the circulation pump, as well as when connecting it to the power supply at home.

The most difficult task is inserting a pumping device into a steel pipeline. However, using a set of guides for creating threads on pipes, you can independently arrange the pumping unit.

Would you like to supplement the information presented in the article with recommendations from personal experience? Or maybe you saw inaccuracies or errors in the material reviewed? Please write to us about this in the comments block.

To increase efficiency, heating systems are additionally equipped with circulation pumps. In order for the expected effect to really be achieved, it must be installed according to all the rules.

Advantages of pump heating

Not so long ago, almost all private houses were equipped with steam heating, which was powered by a gas boiler or a conventional wood stove. The coolant in such systems circulated inside the pipes and batteries by gravity. Only centralized heat supply systems were equipped with pumps for pumping water. After the appearance of more compact devices, they also began to be used in private housing construction.

This solution provided a number of advantages:

1. The coolant circulation rate has increased. The water heated in the boilers was able to flow much faster into the radiators and heat the rooms.
2. The time it takes to heat homes has been significantly reduced.
3. An increase in flow rate entailed an increase in the circuit capacity. This means that smaller pipes can be used to deliver the same amount of heat to its destination. On average, the pipelines were reduced by half, which was facilitated by the forced circulation of water from an embedded pump. This made the systems cheaper and more practical.
4. In this case, to lay highways, you can use a minimum slope without fear of complex and extended water heating schemes. The main thing is to choose the right pump power so that it can create optimal pressure in the circuit.
5. Thanks to household circulation pumps, it has become possible to use heated floors and closed systems of high efficiency, the operation of which requires increased pressure.
6. The new approach made it possible to get rid of many pipes and risers, which did not always fit harmoniously into the interior. Forced circulation opens up possibilities for laying circuits inside walls, under floors and above suspended ceiling structures.

A minimum slope of 2-3 mm per 1 m of pipeline is necessary so that in the event of repairs, the network can be drained by gravity. In classic systems with natural circulation, this figure reaches 5 or more mm/m. As for the disadvantages of forced systems, the most significant of them is the dependence on electrical energy. Therefore, in areas with unstable electricity supplies, it is necessary to use uninterruptible power supplies or an electric generator when installing a circulation pump.

You should also be prepared for an increase in bills for consumed energy (with the correct selection of the power of the unit, costs can be minimized). In addition, leading manufacturers of equipment for heating systems have developed modern modifications of circulation pumps that can operate in increased economy mode. For example, the Alpfa2 model from Grundfos automatically adjusts its performance depending on the needs of the heating system. Such equipment is quite expensive.

The optimal location for installing the circulation pump

Although the Internet is replete with a lot of information on this topic, the average user is not always able to decide on the optimal scheme for connecting the circulation pump to the heating system. The reason is the contradictory nature of the information provided, which is why heated discussions constantly arise on thematic forums.

Proponents of installing the device exclusively on the return pipeline cite the following arguments in defense of their position:

• A higher temperature of the coolant in the supply compared to the return provokes a significant reduction in the service life of the pump.
• The hot water inside the supply line is less dense, which creates additional difficulties in pumping it.
• In the return pipeline, the coolant has a high static pressure, which facilitates the operation of the pump.

Often, such a conviction also comes from accidentally seeing where the circulation pump for heating is installed in traditional boiler houses: there the pumps are, indeed, sometimes connected to the return line. At the same time, in other boiler houses, centrifugal pumps can be installed on supply pipes.

The arguments against each of the above arguments in favor of installation on the return pipe are as follows:

1. The resistance of household circulation pumps to coolant temperature usually reaches +110 degrees, while inside autonomous heating systems the water rarely heats up above +70 degrees. As for boilers, they output a coolant temperature of approximately +90 degrees.
2. Water at a temperature of +50 degrees has a density of 988 kg/m³, and at +70 degrees – 977.8 kg/m³. For devices that create a pressure of 4-6 m of water column and are capable of pumping approximately a ton of coolant in 1 hour, such a tiny difference in density of 10 kg/m³ (capacity of a 10-liter canister) does not play a significant role.
3. The actual difference in the static pressure of the coolant inside the supply and return is also minimal.

As a conclusion, we can say that the connection diagram for the circulation pump may involve its installation on both the return and supply pipes of the heating circuit. This or that option of where to install the circulation pump in the heating system does not have a significant impact on its level of performance and efficiency. The exception is the use of inexpensive solid fuel direct combustion boilers, which do not have automation. Since burning fuel in such heaters cannot be quickly extinguished, this often provokes boiling of the coolant. If the heating pump was connected to the supply pipe, this allows the resulting steam, along with hot water, to enter the housing with the impeller.

• The device sharply reduces its productivity, since its impeller is not able to move gases. This provokes a decrease in the coolant circulation rate.
• There is a decrease in the cooling water entering the boiler tank. As a result, the device overheats even more, and steam production increases.
• After the volume of steam reaches critical values, it enters the impeller. After this, the circulation of the coolant completely stops: an emergency situation occurs. The pressure in the system increases, causing the activated safety valve to release clouds of steam inside the boiler room.
• If you do not extinguish the firewood, then at some stage the valve will not cope with the increasing pressure. As a result, there is a real danger of a boiler explosion.

Cheap heat generators made of thin metal are usually equipped with safety valves with a response threshold of 2 bar. Better quality boilers can withstand pressure surges of up to 3 bar. Based on experience, it can be said that between the onset of overheating and the time when the valve operates, approximately 5 minutes pass.

If the installation scheme of the circulation pump in the heating system involves its installation on the return pipe, then this protects the device from direct exposure to water vapor. As a result, the period of time before an accident increases (by almost 15 minutes). That is, this does not prevent an explosion, but only gives additional time to take emergency measures to eliminate the resulting system overload. Therefore, when looking for a place to install a heating pump, in cases with the simplest wood-burning boilers, it is better to choose a return pipeline for this. Modern automated pellet heaters can be installed in any convenient area.

What are the installation schemes in various heating systems?

The first thing you need to figure out is where to place the pump in the heating system: thanks to it, water will pass through the boiler and be forced into the heating radiators. For this purpose, it is advisable to choose the place where it will be most convenient to service the device. It is mounted on the supply pipe immediately behind the safety group and shut-off valves.

The scheme for installing a circulation pump on the return line involves placing the pump immediately after the boiler. It is advisable to use a combination with a dirt filter: this will eliminate the need to purchase and install additional valves. Similar options for how to connect a heating pump can be successfully used in both closed and open circuits. This is also true for collector systems in which autonomous connections are used to move the coolant to the radiators: they are switched to the distribution comb.

The open-type heating system, designed to operate in two modes - forced and gravity - deserves special attention. This versatility is very convenient in cases where electricity is supplied intermittently, and installing an uninterruptible power supply unit or generator is impossible for one reason or another. In such a situation, the connection diagram for the heating pump of a private house involves placing the device and shut-off valves on the bypass.

Specialized stores offer already assembled bypass units with a pump, in which the flow valve is replaced with a check valve. This approach to installing the pump in the heating system is not correct due to the resistance created by the spring-type check valve in the region of 0.08-0.1 Bar. This is too much for a heating system with natural circulation. Replace the spring valve with a petal valve, which is mounted exclusively in a horizontal position.

It is also important to understand where to install the circulation pump in a heating system with a solid fuel boiler. As already mentioned, the best place for this is the pipe section in front of the heat generator. Typically, in such a piping, together with the pump, a bypass and a three-way mixing valve are also embedded into the boiler circuit.

Rules for installation in a heating system

Regardless of the type of design of the circulation pump, it is installed on a pipeline or shut-off valve using American union nuts. This makes it possible to quickly dismantle in case of repair or replacement of the device.

1. The unit can be embedded in any part of the pipeline - horizontal, vertical or inclined. The main thing is to maintain the horizontal orientation of the rotor axis (the head should never look down or up).
2. It is very important that the plastic container with electrical contacts is placed on top of the case, otherwise it will be flooded with water during an accident. In addition, this will significantly complicate the maintenance of the device. This is quite simple to do by unscrewing the screws securing the box and turning it in the desired direction.
3. The arrow on the pump body indicates the direction of coolant flow, which is important to observe.
4. To simplify maintenance and repair of the device, it is recommended to equip it with shut-off valves on both sides. This will allow you to avoid draining water from the circuit during dismantling.

With this installation scheme for the heating pump, the entire load from its mass falls on 1 or 2 ball valves: their number depends on the spatial orientation of the device. Therefore, it is better not to save money, but to purchase high-quality shut-off valves, the body of which has good mechanical strength.

Installation of additional equipment and its connection

Typically, closed or open radiator systems with one boiler are equipped with one circulation pump. More complex schemes require additional water pumping devices.

We are talking about such cases:

• A private house is heated by more than one boiler system.
• The boiler piping does not have a buffer tank.
• The heating circuit includes several branches for servicing various devices - radiators, heated floors, indirect heating boiler, etc.
• If a hydraulic separator is used.
• Water supply for heated floors is organized.

In order to properly connect several boilers operating on different types of fuel, you will need to provide each of them with a separate pump. A system with a buffer tank requires a heating circuit with two pumps, because We are talking about at least two circulation circuits - boiler and heating.

Highly complex heating schemes with several circuits deserve special mention: they are usually used in large cottages with 2-4 floors. In this case, you may need from 3 to 8 pumps to supply coolant to each floor and to different heating devices. A heating circuit with two pumps is used in cases where the house has two water floors. In some cases, connecting a pump to the heating system of a private house is not required at all, because Most electric and gas wall-mounted boilers have their own pumping devices.

How to connect a circulation pump to electricity

The electrical circuit for connecting the heating pump can be implemented as follows:

• Using a differential machine. The simplest option that can be implemented independently without any problems.
• Thermostat control. Makes it possible to automatically stop the movement of the coolant if its temperature drops below a certain level.
• Combined use of network and uninterruptible power supply unit. Connecting power via a UPS is a snap thanks to special connectors. The same cannot be said about the procedure for connecting the pump to the distribution panel: for this it is better to call a specialist.
• Powered by built-in automation. The organization of such an electrical circuit for a circulation pump will require some knowledge in the field of electrical engineering.

It is not recommended to use a simple socket without automation or grounding to switch the device.

Optimal pump speed

The task of a heating system with pump circulation is to reliably deliver coolant to all consumers of the system, including the furthest radiators. For this to happen effectively, the pump must create the pressure necessary for this: the designers calculate it, taking into account the hydraulic resistance of the pipes. Most often, household pumps have 3-7 rotor speeds, which allows you to increase or decrease work productivity.

The easiest way to select the optimal speed of the circulation pump:

1. The heating system must be brought into operating mode.
2. Measure the pipe surface temperature before and after the boiler using a laser surface thermometer (pyrometer).
3. If the temperature difference is more than 20 degrees, the rotor rotation speed must be increased.
4. If the difference is less than 10 degrees, the flow rate must be reduced. The optimal difference between the supply and return heating levels is approximately 15 degrees.

The pyrometer need not be used when the supply and return pipes are equipped with thermometers. If, with the help of adjustments, it is not possible to achieve the required temperature difference of 10-20 degrees, this indicates low efficiency of the system. The cause is most often an error in the selection of the circulation apparatus. Too low a return water temperature provokes an increase in the load on the boiler and an increase in energy consumption. Very hot water circulates too quickly to transfer heat to the heaters.

To make heated water flow more cheerfully through the pipes, a circulation pump is installed in the heating systems of private houses. This solution provides tangible benefits. But the main question that worries homeowners and is covered in this material is where it is better to install the pump and how to install it correctly. After all, the main part of the controversy and doubt is caused by the place where the unit is inserted. And at the same time, we’ll figure out how to connect it to the house electrical network with our own hands.

What are the benefits of pump heating systems?

30 years ago, so-called steam heating was common in private homes, where the coolant circulated through pipes and radiators by gravity, and the heat source was a gas boiler or wood stove. Pumps for pumping water were used in district heating networks. When compact circulation pumps for heating appeared, they migrated to private housing construction, as they provided the following advantages:

1. The speed of coolant movement has increased. The heat generated by the boiler has become faster delivered to the radiators and transferred to the premises.
2. Accordingly, the process of heating the house has accelerated significantly.
3. The higher the flow rate, the greater the throughput of the pipe. This means that the same amount of heat can be delivered to rooms through lines of smaller diameter. Simply put, the pipelines have become half the size thanks to the forced circulation of water from the pump, which is cheaper and more practical.
4. Highways can now be laid with a minimum slope and water heating circuits can be made as complex and extensive as desired. The main thing is the correct selection of the pumping unit in terms of power and pressure created.
5. The household circulation pump for heating has made it possible to organize underfloor heating and more efficient closed systems operating under pressure.
6. It was possible to remove from view the ubiquitous pipes that run through the rooms and do not always harmonize with the interior. Increasingly, heating communications are laid in walls, under floor coverings and behind suspended (suspended) ceilings.

Note. A minimum slope of 2-3 mm per 1 m of pipeline is needed to empty the network in case of repair or maintenance. Previously, it was made at least 5 mm / 1 m.p.

Pumping systems also have disadvantages. This is a dependence on electricity and its consumption by the pumping unit during the heating season. Therefore, if there are frequent power outages, the circulation pump must be installed together with an uninterruptible power supply unit or connected to an electric generator. The second drawback is not critical; if you select the power of the device correctly, then the electricity consumption will be acceptable.

Leading manufacturers of heating equipment, such as Grundfos or Wilo, have developed new models of units that can save energy. For example, if you buy and install an Alpfa2 circulation pump from the Grundfos brand, it will automatically change its performance depending on the needs of the heating system. True, its price starts from 120 USD. e.

New generation circulation units from Grundfos – models Alpfa2 and Alpfa2L

Where to install the pump - supply or return

Despite the abundance of information on the Internet, it is quite difficult for the user to understand how to correctly install a heating pump in order to ensure forced circulation of water in the system of their own home. The reason is the inconsistency of this information, which causes constant debate on thematic forums. Most of the so-called specialists claim that the unit is installed only on the return pipeline, citing the following conclusions:

• the coolant temperature in the supply is much higher than in the return, so the pump will not last long;
• The density of hot water in the supply line is less, so it is more difficult to pump;
• The static pressure in the return line is higher, which makes the pump easier to operate.

Interesting fact. Sometimes a person accidentally ends up in a boiler room that provides central heating for apartments, and sees the units there embedded in the return line. After this, he considers this solution to be the only correct one, although he does not know that in other boiler houses centrifugal pumps can also be installed on the supply pipe.

We respond to the above statements point by point:

1. Household circulation pumps are designed for a maximum coolant temperature of 110 °C. In a home heating network it rarely rises above 70 degrees, and the boiler will not heat the water more than 90 °C.
2. The density of water at 50 degrees is 988 kg/m³, and at 70 °C – 977.8 kg/m³. For a unit that develops a pressure of 4-6 m of water column and is capable of pumping about a ton of coolant in 1 hour, the difference in the density of the transported medium is 10 kg/m³ (the volume of a ten-liter canister) is simply negligible.
3. In practice, the difference in static pressure of the coolant in the supply and return lines is equally insignificant.

Here's a simple conclusion: Circulation pumps for heating can be embedded into both the return and supply pipelines of the heating system of a private house. This factor will not in any way affect the performance of the unit or the heating efficiency of the building.

Boiler room made by our expert Vladimir Sukhorukov. There is convenient access to all equipment, including pumps.

The exception is cheap solid fuel direct combustion boilers that are not equipped with automation. When overheated, the coolant in them boils, since burning wood cannot be extinguished at once. If the circulation pump is installed on the supply side, then the resulting steam mixed with water enters the housing with the impeller. The further process looks like this:

1. The impeller of the pumping device is not designed to move gases. Therefore, the performance of the device decreases sharply, and the flow rate of the coolant drops.
2. Less cooling water enters the boiler tank, causing overheating to increase and even more steam to be produced.
3. An increase in the amount of steam and its entry into the impeller leads to a complete stop of the coolant movement in the system. An emergency situation occurs and, as a result of an increase in pressure, a safety valve is activated, releasing steam directly into the boiler room.
4. If no measures are taken to extinguish the firewood, the valve cannot cope with the pressure release and an explosion occurs with the destruction of the boiler shell.

For reference. In cheap heat generators made of thin metal, the response threshold of the safety valve is 2 Bar. In higher quality TT boilers, this threshold is set at 3 Bar.

Practice shows that no more than 5 minutes pass from the start of the overheating process to the valve activation. If you install a circulation pump on the return pipe, then steam will not enter it and the time period before an accident will increase to 20 minutes. That is, installing the unit on the return line will not prevent an explosion, but will delay it, which will give more time to fix the problem. Hence the recommendation: it is better to install pumps for boilers running on wood and coal on the return pipeline.

For well-automated pellet heaters, the installation location does not matter. You will learn more information on the topic from our expert’s video:

Installation diagrams in various types of systems

To begin with, let’s clarify the place where to install the flow pump, which circulates water through the boiler and forcibly directs it to the radiators of the heating system. According to ours, whose experience is trustworthy, the installation location must be chosen in such a way that the unit is convenient to maintain. On the supply side it should be located after the safety group and shut-off valves, as shown in the installation diagram:

In order for the unit to be removed and serviced, shut-off valves must be installed on the sides

On the return, the pump must be placed directly in front of the heat generator, and in tandem with a filter - a mud trap, so that you do not have to buy and install extra taps. The wiring diagram for the pumping unit looks like this:

When installing on the return line, it is better to place the mud collector in front of the pump unit

Recommendation. A circulation pump can be installed in this way in both a closed and an open heating system, there is not much difference. The statement also applies to the collector system, where the coolant moves to the radiators through separate connections connected to the distribution comb.

A separate issue is an open heating system with a circulation pump, capable of operating in 2 modes - forced and gravity. The latter is useful for homes where power outages often occur, and the owners’ income does not allow them to buy an uninterruptible power supply unit or a generator. Then the device with shut-off valves must be installed on the bypass, and a tap must be inserted into a straight line, as shown in the diagram:

This scheme can operate in forced and gravity mode

Important point. On sale there are ready-made bypass units with a pump, where instead of a tap on the flow there is a check valve. Such a solution cannot be called correct, since a spring-type check valve creates a resistance of the order of 0.08-0.1 Bar, which is too much for a gravity heating system. Instead, you can use a petal valve, but it must be installed only in a horizontal position.

Finally, we will explain how to install and connect a circulation pump to a boiler that burns solid fuel. As mentioned above, it is better to place the unit on the line coming from the heating system to the heat generator, as shown in the diagram:

Installation rules

The design of a household circulation pump from any manufacturer provides for its fastening to pipelines or shut-off valves using union nuts (American). This allows it to be quickly dismantled if necessary, for example, for replacement or repair. When installing the pump unit, follow these recommendations:

1. Place the device on any sections of pipelines - horizontal, vertical or inclined, but with one condition: the rotor axis must be in a horizontal position. That is, installation “head down” or up is unacceptable.
2. Please note that the plastic box with electrical contacts is located on top of the case, otherwise it will be flooded with water in the event of an accident. Yes, and servicing the product will not be easy. This is easy to achieve: unscrew the screws securing the casing and turn it to the desired angle.
3. Remember to follow the flow direction indicated by the arrow on the housing.
4. So that the product can be removed without emptying the system, install shut-off valves before and after it, as shown in the diagrams in the previous section.

A visual aid showing what position the pump unit should be in

Advice. It so happened that the load from the weight of the circulation unit will fall on 1 or 2 ball valves (depending on the orientation of the area in space). Hence the recommendation: do not save money and buy high-quality shut-off valves, whose body will not crack over time from mechanical stress.

About installing additional units

As a rule, in a closed or open radiator heating system, where the heat source is a single boiler, it is enough to install one circulation pump. In more complex schemes, additional units are used for pumping water (there may be 2 or more of them). They are placed in the following cases:

• when more than one boiler installation is used to heat a private house;
• if a buffer tank is involved in the piping scheme;
• the heating system has several branches serving various consumers - radiators, heated floors and an indirect heating boiler;
• the same, using a hydraulic separator (hydraulic arrow);
• for organizing water circulation in underfloor heating circuits.

Correct wiring of several boilers operating on different types of fuel requires that each of them have its own pumping unit, as shown in the diagram for the joint connection of an electric and TT boiler. , described in our other article.

Connecting an electric and TT boiler with two pumping devices

In a circuit with a buffer tank, it is necessary to install an additional pump, because it involves at least 2 circulation circuits - boiler and heating.

The buffer tank divides the system into 2 circuits, although in practice there are more of them

A separate story is a complex heating scheme with several branches, implemented in large cottages with 2-4 floors. Here, from 3 to 8 pumping devices can be used (sometimes more), supplying coolant floor by floor and to different heating devices. An example of such a circuit is shown below.

Finally, a second circulation pump is installed when heating the house with water-heated floors. Together with the mixing unit, it performs the task of preparing coolant with a temperature of 35-45 ° C. is clearly described in a separate material.

This pumping unit forces coolant to circulate through the heating circuits of underfloor heating.

Reminder. Sometimes pumping devices do not need to be installed for heating at all. The fact is that most electric and gas wall-mounted heat generators are equipped with their own pumping units built inside the housing.

Connecting the circulation pump to the electrical network

There are several ways to connect power to the device:

• through a conventional differential machine;
• with thermostat control;
• connection to the network together with an uninterruptible power supply unit (UPS);
• powering the unit from the boiler automation.

Warning. Often, homeowners simply plug the pump into a regular outlet, connecting the wires to a purchased plug. We cannot recommend this approach, because connection without grounding and a safety circuit breaker is dangerous. If there is a problem with the device or if it is filled with water, you risk receiving an electric shock.

Typical connection diagram with differential circuit breaker

The first connection diagram is quite simple and any user can assemble it with his own hands. You will need an 8 A differential circuit breaker, wires and contacts. Connect to grounding both in this circuit and in all others.

To automatically stop the movement of the coolant when cooling to a certain temperature, an electrical circuit is used to connect a circulation pump with a thermostat. The latter is attached to the supply pipeline and breaks the power supply circuit when the water temperature drops below a set value.

Connecting a phase wire to the pump through an overhead thermostat

Attention! To ensure that the thermostat does not lie and turns off the circulation in time, it must be attached to a metal section of the line. Polymers do not transfer heat well, so when mounted on a plastic pipe, the device will not work correctly.

There are no difficulties in connecting the power supply through a UPS, for which the latter has special connectors. The heat generator itself should also be connected to them if it needs electricity. But connecting the pump to the boiler control panel or to its automation is a more complicated procedure. It is advisable to have knowledge and skills in the field of electrical engineering.

The boiler is also connected to the uninterruptible unit if it needs electricity

At what speed should the pump in the heating system operate?

The purpose of forced circulation is to effectively heat the house through the reliable delivery of heat to all consumers of the system, right up to the furthest radiator. To do this, the pumping unit must develop the required pressure (otherwise known as pressure), which is ideally calculated by design engineers based on the hydraulic resistance of the pipeline network.

Most household pumps have from 3 to 7 rotor speeds, due to which the performance and pressure generated can be increased or decreased. In order not to torment you with hydraulic calculations, we offer the following method for selecting the optimal speed:

1. Find a laser surface thermometer (pyrometer). Put the heating system into operating mode.
2. Measure the surface temperature of the pipe at the inlet and outlet of the boiler.
3. If the temperature difference is more than 20 °C, increase the rotor speed. After 30 minutes, repeat the measurement.
4. When the temperature difference is less than 10 °C, the water flow rate must be reduced. The goal is to achieve a delta between supply and return of about 15 °C.

The minimum number of rotor rotation speeds is 3, but sometimes 7 or more

Advice. Do not switch the pump to a different circulation speed “on the fly”. Disconnect it from the network, move the regulator to a different position, and then put it back into operation.

You can do without a pyrometer when thermometers are installed on the supply and return lines. If the adjustment limits do not allow you to enter the range of 10-20 °C temperature difference, your system is not working efficiently due to an incorrectly selected circulation pump. Too cold return water increases the load on the boiler and increases fuel consumption. Water that is too hot means that it flows too quickly and does not have time to transfer heat to the heating devices.

The leading European brand Grundfos offers the latest generation Alpfa3 circulation pumps, which can independently select performance depending on the load and thus adapt the work to changing conditions. With their help, you can even balance the heating system, which our expert will tell you about in the next video:

Conclusion

Now you know how to properly install a circulation pump in a water heating system and connect it to the power supply of a country house. This will save you from making all sorts of mistakes that lead to minor and major troubles. Again, you can install and wire the unit yourself. The only difficulty is to embed it into a section of steel pipeline. But there is a way out: find a set of tools for manually cutting pipe threads, cut out a piece of pipe with a grinder and mount the pump unit.