To distribute heat evenly in a house equipped with an autonomous heating system, various models of circulation pumps are used. This equipment provides forced circulation of coolant through pipes and radiators. In this case, the radiators are heated simultaneously in all rooms, regardless of their distance from the heating boiler.

The heating pump is installed in accordance with the manufacturer’s instructions, which describe in detail the installation process of this equipment. In practice, several methods of arranging pumping units in the heating system of a private house have been tested. In each case, the owner of the facility selects the most suitable option, taking into account the type of boiler and expansion tank used, the type of heating system, and the presence of additional elements.

Selecting the right unit

When choosing a circulation pump for an autonomous heating system, they are guided by two main criteria - unit performance and pressure. The first of these parameters characterizes the volume of coolant that the unit can pump over a certain period of time, and the second indicates the height to which the pump can lift the liquid. In addition, you need to consider:

  1. The cross-section of pipes to which the circulation pump will be connected.
  2. Dimensions of the space allocated for installation of the pumping unit.
  3. Maximum coolant temperature.
  4. Power and throughput of the heat generator.
  5. Volume of heated premises.

We have already talked about the classical calculation method in the article. At the same time, there is a simpler method that can be used both for preliminary calculations and for checking the results of more thorough calculations. It is based on the requirement that the circulation pump must pump three times its filling volume through the heating system in one hour of operation.

The last value can be indirectly estimated from the power characteristics of the boiler. If the thermal unit was selected according to the rules, then for every kilowatt taken from its technical data sheet there are at least 15 liters of coolant. It is enough to multiply the power of the heat generator in kW by 15 and make a correction of 20% in order to estimate the filling of the heating circuits with sufficient accuracy. After the volume of coolant has been calculated, it will not be difficult to calculate the required performance of the circulation pump in l/min - to do this, the filling of the circuits in liters must be multiplied by three and divided by sixty. If we take a heating system with a 15 kW boiler as an example, we can assume that the volume of liquid in all its branches is approximately 270 liters (Q = 15 kW x 15 l + 20%). For forced circulation of coolant, you will need a pump with a flow rate of at least 0.81 m 3 /hour or 13.5 l/min.

The required pressure value of the circulation pump can also be determined without going into complex mathematical calculations. To do this, you can use the formula N = X * K, where X is the number of floors of the building, including the basement, and K is a correction factor equal to 0.7-1.1 for traditional two-pipe heating schemes and 1.2-1.85 for collector-radial circuits. So, if you calculate the hydraulic resistance of a collector heating system of a two-story building with a basement (the number of levels is three), then you will need a pump with a pressure of 3x1.85 = 5.55 m.

The obtained values ​​will already be enough to decide on a specific model of a circulation pump from any manufacturer. To do this, the operating point is found on the graphs of the hydraulic characteristics of centrifugal units - it is located at the intersection of the segments drawn from the abscissa (performance) and ordinate (pressure) axis. The best position of the operating point is considered to be the middle third of the graph, which corresponds to the maximum efficiency.

The graph of the hydraulic characteristics of the circulation pump allows you to analyze whether the unit meets the requirements for pressure and performance

To obtain a sufficient reserve in both directions, you should focus on the curve constructed for the average speed of the circulation pump. In this case, it will be possible to reduce its power if there is excessive noise or increase it if the coolant at the entrance to the boiler has an unacceptably low temperature.

Features of the design of a heating system with pump circulation are studied in this article:

Thermal valves installed in many heating systems regulate the room temperature in accordance with the specified parameters. The valve closes when the temperature rises. This increases hydraulic resistance and, accordingly, increases pressure. These processes are accompanied by the appearance of noise, which can be eliminated by switching the pump to low speed. Pumps with built-in electronics that can smoothly regulate pressure drops depending on changes in the amount of water cope with this task more effectively.

Determining where the pump is inserted into the system

When installing a circulation pump, it is necessary to take into account not only the manufacturers' recommendations, but also the possibility of its periodic maintenance. More recently, it was recommended to install pumps with a “wet” rotor exclusively on the return line - it was believed that this way they would work much longer, since they would be in a more gentle temperature regime.

Typical diagram for connecting a pump providing forced circulation of coolant to an autonomous heating system of a private house or country cottage

Modern units are designed for long-term contact with hot liquid, so they can be safely installed on the supply side. Moreover, experts often recommend installing the pump on the supply pipeline in order to increase the pressure in the suction zone. In this case, the specified area will have the highest temperature, so you must ensure that the electrical device is capable of contact with high-temperature liquid. The advantages of this method can be appreciated, for example, by owners of warm water floors, since in this case the formation of air pockets is eliminated.

For heating systems with membrane tanks, on the contrary, it is recommended to install a bypass with a pump on the return side, closer to the expansion tank. If such a scheme makes it difficult to service the pump, then it is cut directly into the main line, always equipping the circuit with a check valve.

Choosing a circulation pump and deciding where to install it is only half the battle. It is equally important to carry out the piping correctly - only in this case can you count on long, trouble-free operation and the possibility of comfortable servicing of the unit. There is nothing complicated in the recommendations of experts:

  1. The pump installation location should be equipped with ball valves. With their help, it will be possible to isolate the unit from the coolant during preventive or repair measures.
  2. On the coolant inlet side, it is necessary to install a coarse filter, which will serve as a barrier to mechanical particles. As practice shows, the presence of such a device slows down the process of abrasive wear of the impeller several times. If we talk about the danger of damage to the pump, then the importance of filtration is difficult to overestimate.
  3. The uppermost point of the bypass should be equipped with a venting valve.
  4. The direction of movement of the coolant must coincide with the arrow on the device body.
  5. Since in “wet” type pumps cooling and lubrication is performed by the pumped coolant, the axis of rotation must be parallel to the horizontal.
  6. To ensure tightness, mating parts and their joints are sealed using gaskets and sealants.

It is equally important to correctly connect the pump to the electrical network. The type and cross-section of the cable must correspond to the power of the unit, and the connection must be made only with protective grounding.

Basic installation rules

Any equipment is supplied accompanied by the manufacturer’s instructions, which reflect all the important information about its design, operating principle and installation rules. After reading this technical document carefully, you can understand the basic rules for handling it.

When installing it yourself, it is very important to choose the desired position of the product relative to the horizon. The location of the electric motor shaft must be strictly horizontal. Otherwise, air pockets may form, which will leave the bearings without lubrication and sufficient cooling. This will lead to rapid wear of parts and rapid equipment breakdown. There is an arrow on the pump body in the direction in which the coolant in the system should move.

Options for correct and incorrect placement of a circulation pump with a “wet” rotor. It is strictly prohibited to place equipment as shown in the bottom row.

The need for water filtration

A sump tank is installed in front of the pump, the function of which is to filter the coolant. The mud filter traps abrasive particles, sand, scale and other contaminants that get into the water. If such elements get inside the pump, the impeller and bearings may be destroyed. Since the diameter of the insert for mounting the pump is small, you can use an ordinary coarse filter. Please note that the barrel, which serves to collect various suspensions, is directed downward. Being in this position, the filter will not serve as an obstacle to water circulation. When partially filled, the barrel will not lose its ability to pass coolant.

Important! Most filters are equipped with an arrow indicating the correct direction of water flow in the circuit. If you ignore the direction of the arrow, you will have to clean the mud pan much more often.

Pump location in the heating circuit

In principle, most models of modern pumps can work equally well on both supply and return. The equipment can be installed in any part of the heating circuit. It should be taken into account that the duration of operation of the bearings and plastic parts of the device will depend on the temperature of the coolant. Therefore, it is better to install the equipment on the return pipeline after the expansion membrane tank and before the heating boiler.

One of the options for correctly inserting a circulation pump into the pipeline of the heating system of a private house with a circuit length of no more than 80 meters

Why is bypass needed?

The circulation pump is a volatile device. When there is a power outage, the heating system must operate under natural circulation conditions. To do this, it is necessary to minimize resistance in the circuit by reducing the number of bends and turns, as well as using modern ball valves as shut-off valves. When open, the clearance in the ball valve coincides with the diameter of the pipe.

The circulation pump is installed on, which is cut off from the main system using two ball valves. This placement of the equipment allows it to be repaired or replaced without damaging the heating system of the house. In the off-season, the heating system can operate without a pump, which is shut off using the same ball valves. When frost intensifies, the pump is put into operation by opening the shut-off valves along its edges and closing the ball valve on the main circuit. This is how the direction of coolant flow is adjusted.

Installation of the circulation pump on the bypass (bypass pipe) using three ball valves ensures the coolant flow in the desired direction

Electrical connection

If the heating system is designed on the principle of forced circulation, then in the event of a power outage the pump must continue to operate from a backup power source. Therefore, it is recommended to install an uninterruptible power supply that will allow the heating system to function for a couple of hours. This time is usually enough for specialists to eliminate the cause of an emergency power outage. External batteries connected to a backup power source can extend the battery life of the equipment.

Connecting the pump to an uninterruptible power supply (UPS), which is additionally reinforced by three battery units connected in series into a single circuit

When making electrical connections to the equipment, it is necessary to eliminate the possibility of moisture and condensation getting into the terminal box. A heat-resistant cable is used if the coolant heats up in the heating system by more than 90° C. Contact of the power cable with the walls of pipes, the engine, or the pump housing is not allowed. The power cable is connected to the terminal box from the left or right side, and the plug is rearranged. When the terminal box is located on the side, the cable is inserted only from the bottom. And yes, grounding is required!

The following material will help answer the question of why install a circulation pump:

Checking operation and putting it into operation

After completion of installation work, the heating system is filled with water. The air is then removed by opening the central screw located on the pump housing cover. The appearance of water will indicate the complete removal of air bubbles from the device. After this, the pump can be put into operation.

After reading the instructions and reading this article, you can carry out the installation work yourself. If you do not understand how to install a heating pump, then invite a professional technician.

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.

Modern home heating systems that use forced circulation, due to the impossibility of maintaining all slopes or the significant length of the pipeline, require the installation of a circulation pump. The main task of this device is to ensure constant circulation of the coolant.

Features of choosing a pump for heating systems

The main criteria that you should rely on when choosing circulation-type pumping equipment:

  • density and kinematic viscosity of the coolant used in the system. If the viscosity of the pumped liquid exceeds the parameters recommended by the manufacturer, the hydraulic characteristics of the device will decrease;
  • equipment power. There is no point in buying an overly powerful device. Firstly, it will not work at full capacity, and secondly, it will create noise interference. If you decide to connect a circulation pump to a system with a complex architecture with your own hands, you should entrust the calculation of the equipment’s power to an experienced technical engineer. To independently determine the optimal device model, you can use the following tips.

The ability of a device to meet the needs of the system loop depends on the following characteristics:

  • coolant volume and pressure,
  • pipeline diameter,
  • temperature and density of the pumped liquid.

The flow rate of the coolant (Q) passing through a given section of the closed circuit is equal to the flow rate and power parameters of the heating boiler (P=Q). So, if the boiler power is 20 kW, then 20 liters of water can pass through it per minute.

Batteries with a power of 10 kW can consume up to 10 liters of water per minute. Using this data, you can calculate the water flow in the system rings.

The level of water flow in pipes directly depends on their diameter. The narrower the pipes, the higher the resistance in the path of coolant movement. The table below is compiled taking into account the standard speed of movement through water pipes (1.5 m/sec).

The power of pumping equipment is directly proportional to the length of the pipeline. It turns out that for every 10 m section of the heating system, 0.6 m of pump pressure is required.

To select a device more accurately, you should also take into account the type of material from which the pipes are made, the type of automation and shut-off valves, and the number of heating appliances in the house.

Approximately for a house with an area of ​​up to 250 m2, a circulation pump for heating is required with a capacity of 3.5 m3/h, a pressure of up to 0.4 atm., installation of equipment for a house with an area of ​​up to 350 m2 - with a capacity of 4.5 m3/h and a pressure of up to 0.6 atm., for buildings with an area of ​​up to 800 m2 - with a capacity of 11 m3/h and a pressure of up to 0.8 atm.

The initial stage of installation of the circulation pump

So, the device model has been selected, now you should study the instructions from the manufacturer. Be sure to take into account the fact that the heating system will need maintenance from time to time. Carefully read the heating circulation pump connection diagram.

When choosing a location for equipment, you must remember that periodically you will have to check and adjust the network. Don’t forget about the shut-off valves that will need to be installed at the inlet or outlet of the pump.

Pumps with a “wet” rotor should be installed on the “return” side. However, today you can purchase equipment with components and parts made from materials that can withstand high temperatures. Such units can be installed on the return and supply pipes.

If you want to increase the pressure in the suction area, install the equipment on the supply pipe close to the expansion tank.

If the house has a “warm floor” system, it is best to install the pump on the hot water supply line. This will avoid the formation of air pockets.

The sequence of connecting the pump to the heating system

  • We remove the liquid from the system and, if necessary, clean the pipeline. In order to understand how to properly connect the circulation pump, you must thoroughly study the diagram.

  • Prepare wrenches (sizes 22-36), a piece of pipe for the bypass, and shut-off valves.
  • In search of an answer to the question of how to properly install a circulation pump, experts came to the conclusion that it is best to place it in front of the boiler on the return line. This decision is explained by the fact that air pockets can form at the top of the boiler over time, and if you install pumping equipment on the supply side, it will draw air out of the boiler. This can cause a vacuum to form and cause the boiler to boil. If the pump is placed in front of the boiler, the liquid will be thrown into it, while the heating device will remain filled. In this case, the equipment will be able to function normally at low temperatures, which will have a positive effect on its service life.
  • After we have decided how and where to install the circulation pump, we perform a bypass. It is needed so that in the event of a power outage or device breakdown, the system does not stop working, and the coolant flows through the main pipeline with the taps open. The diameter of the main pipeline must exceed the diameter of the bypass. After the bypass installation work is completed, we proceed to install the circulation pump, which we also do ourselves.
  • It is important to remember that the device must be positioned horizontally, otherwise only some part of it will end up in the water. This can lead to a reduction in equipment productivity by 30% or more, and in some cases can lead to a complete breakdown of the work area. Make sure that the terminal box is at the top.
  • Ball valves are installed on the sides of the pump, which are needed for maintenance and dismantling of equipment.
  • To protect the heating system from the ingress of small mechanical particles that could harm the pumping device, a filter is installed.

  • The valve should be located on top of the bypass pipe. It is needed to periodically remove air locks.
  • The degree of risk of coolant leakage in the pump inlet-outlet area depends on how well the shut-off valves are secured.
  • When securing the motor shaft, ensure the necessary rotation of the box along the axis. If the house uses an open heating system, an expansion tank will be required.
  • All connections should be carefully treated with sealant.

  • To install the pump, a device with detachable threads is used.
  • If the length of the system pipeline exceeds 80 meters, you will need to install another circulation pump.
  • The cost of carrying out the above measures depends not only on the model of the device being installed, but also on the number of pipeline circuits and the complexity of installing bypass pipes.

After the installation cycle is completed, the system should be filled with water, remove excess air using a screw, and only then turn on the pump. This sequence of actions must be followed each time the device is turned on. If it is difficult for you to perform these operations manually, choose to install a pump equipped with automatic systems for monitoring the operation and protecting the unit.

Circulation pumps are becoming more and more common modules in home heating systems. They ensure proper circulation of the coolant, which contributes to uniform heating of the entire household. The service life of modern models reaches 10-15 years. Let's see how to choose and install the right water pump for heating a house and why it is needed in general.

The need for circulation pumps

Before we tell you how to properly install a circulation pump for heating your home, let's talk a little about why it is needed in a heating system. Thin plastic pipes have appeared on sale quite recently. Their predecessors are thicker, large-diameter metal pipes. Possessing a solid margin of safety and increased throughput, they ensured the unhindered flow of coolant through the heating system.

Previously, water pumps were not needed, since thick pipes did not create serious hydrostatic resistance. The design of old heating devices should also be noted - their impressive internal volumes did not create any special obstacles to the flow of coolant. Only the circuits had to be mounted according to a special scheme:

  • A high pipe was installed from the boiler, raising the coolant above all heating devices;
  • An expansion tank was mounted at the highest point;
  • The supply pipe was mounted at an angle so that the coolant flows freely towards the radiators;
  • The return pipe had to be installed at an angle towards the heating boiler.

This scheme, which did not include water pumps, ensured excellent heating performance.

Problems were created only if it was necessary to heat a large house. In this case, the coolant flows through the system with difficulty, since the large circuit creates high resistance. The longer the pipes and the more heating devices, the more obstacles there are. In two-story mansions, the resistance reaches the highest values. As a result, we observe:

The voiced problems can be solved in two ways - by more carefully designing the heating system circuit or by using a water pump.

  • Uneven heating of the heating system;
  • Cold branches;
  • Boiler water overheating.

Features of modern heating systems

A water heating pump is a small device with an electric motor and an impeller that ensures normal coolant circulation in the system. In modern heating it is impossible to do without it - a large number of bends, a small clearance of plastic and metal-plastic pipes, as well as the small capacity of heating devices affect it.

This number of obstacles causes an increase in hydrostatic resistance in the heating system. The abundance of additional elements also has an effect - these are thermostatic valves, manifolds, hydraulic arrows and much more. Many problems are created by the desire to hide all the pipes in the walls so that only the radiators are visible from the outside - in this case, you cannot do without a water pump for heating the house.

Adding fuel to the fire is the complete absence of slopes in modern heating - all pipes are located in a horizontal plane, without deviations in height.

Water pumps are in demand in closed heating systems. Here the coolant flows in a closed circuit without contacting the atmosphere. To install the systems, thin plastic pipes are used, so it is simply impossible to ensure normal flow of coolant here - it is necessary to install a water pump for heating.

The pump can also be installed in an open-type heating system, immediately after the heating boiler, but always before the expansion tank, and not after it.

Two pumps in the heating system or more

In order to ensure economical heating operation, we recommend purchasing more advanced energy-saving models of water pumps.

The water pump for circulating water in the heating of a private house is often not the only one in the system. Water-based heated floors have become a fashion in recent years. They provide heating for floor coverings, creating a comfortable atmosphere for people to stay. Since the basis for their manufacture is thin pipes made of cross-linked polyethylene, independent circulation of the coolant in them is impossible. Therefore, an additional pump is installed in the system.

Underfloor heating systems require the installation of a water pump. It is placed in the distribution box, next to the thermostatic valves, after which it must be connected to the mains. It works only in the underfloor heating circuit, while the second pump circulates the coolant through the rest of the heating circuit.

There are also diagrams of heating systems with several heating circuits. When planning to create independent heating for floors and rooms, consumers think about how many pumps are needed to heat a private home. One electric pump is installed here as a common one, in the supply or return, then a separate pump is installed for each circuit.

How to choose a water pump for heating your home

A heating pump for a private home is selected according to several basic parameters:

  • Productivity and pressure;
  • Rotor type;
  • Power consumption;
  • Control type;
  • Coolant temperature.

Let's look at how to choose water pumps for heating a private home.

Performance and pressure

Correctly made calculations will help you choose the unit that best suits your needs, which means it will help you save your family budget.

The performance of an electric water pump refers to its ability to move a certain amount of water per minute. The following formula is used for calculation – G=W/(∆t*C). Here C is the thermal capacity of the coolant, expressed in Wh/(kg*°C), ∆t is the temperature difference in the return and supply pipes, W is the required heating power for your home.

The recommended temperature difference when using radiators is 20 degrees. Since water is usually used as a coolant, its heat capacity is 1.16 W*h/(kg*°C). Thermal power is calculated for each household individually and expressed in kilowatts. Plug these values ​​into the formula and get the results.

The pressure is calculated in accordance with the pressure loss in the system and is expressed in meters. Losses are calculated as follows - losses in pipes are considered (150 Pa/m), as well as in other elements (boiler, water purification filters, radiators). All this is added up and multiplied by a factor of 1.3 (provides a small margin of 30% for losses in fittings, bends, etc.). There is 9807 Pa in one meter, therefore, we divide the value obtained by summation by 9807 and obtain the required pressure.

Rotor type

Home heating uses wet rotor water pumps. They are characterized by a simple design, minimal noise levels and no need for maintenance. They are also characterized by small dimensions. Lubrication and cooling in them is carried out using a coolant.

As for dry-type water pumps, they are not used in home heating. They are bulky, have a high noise level, and require cooling and periodic lubrication. They also require periodic replacement of seals. But they have a large throughput capacity - for this reason they are used in heating systems of multi-storey buildings and large industrial, administrative and utility buildings.

Power consumption

The most modern water pumps with energy consumption class “A” have the lowest power consumption. Their disadvantage is their high cost, but it is better to invest once to get reasonable energy savings. In addition, expensive electric pumps have lower noise levels and a longer service life.

Control type

Through a special application you can get information about the operation of the device wherever you are.

Typically, the rotation speed, productivity and pressure are adjusted using a three-position switch. More advanced pumps are equipped with electronic control systems. They control the parameters of heating systems and allow you to save energy. The most advanced models are controlled wirelessly, directly from a smartphone.

Coolant temperature

Water pumps for heating a private home differ in their operating temperature range. Some models can withstand heating up to +130-140 degrees, these are the ones that should be preferred - they can cope with any thermal loads.

As practice shows, operation at the maximum temperature is possible only for a very short time, so having a solid reserve will be a plus.

Other characteristics

When choosing a water pump for heating, you need to pay attention to the maximum operating pressure for the selected model, installation length (130 or 180 mm), type of connection (flange or coupling), and the presence of an automatic air vent. Also pay attention to the brand - under no circumstances buy cheap models from little-known developers. The water pump is not a part you should skimp on.

Connecting the circulation pump to the heating system

Installing a circulation pump in the heating system of a private house begins with choosing its location. You need to decide where to make the tie-in - in the supply or in the return. The last option is the most common. In open-type systems, it can also be installed on the supply pipe, but only immediately after the boiler, before the expansion tank.

Also, the installation rules state that there should be no vacuum in the boiler heat exchanger - it is created by water pumps. Therefore, the optimal placement location is the return pipe, not the supply pipe.

Placing water heating pumps for a home in the return pipe has a very important advantage - the temperature of the coolant in this area is lower, which ensures good cooling of the electric pump. In the supply pipe it will operate at a temperature close to the maximum value, and this is already minutes.

In the case of heated floors, the pump is mounted in a distribution cabinet. When using several circuits, water pumps are mounted as far as possible from the boiler, behind the hydraulic arrow - one pump for each direction. Placement on the supply pipe is also possible if the circuit does not branch, but it is too long - in this case the electric pump is placed away from the heating boiler.

Proper installation of an additional pump ensures that it is powered and turned on separately from other pumps in the system.

Position of the water pump in space

We have already decided where to install the circulation pump for heating and have developed brief instructions - if the circuit does not branch, we place it on the return line. In the case of several circuits, the connection diagram will be different - we install a pump on the supply pipes in each direction.

Regardless of where the water pump for home heating will be installed, its rotor axis must be located strictly in a horizontal position. Along other axes its position can be arbitrary. But its electrical circuit should not be located at the bottom, for which there is a completely logical explanation - if the unit fails, the electrical circuit will be flooded with coolant, which will cause a short circuit.

Carrying out installation work

The water pump is installed in the heating system through a bypass. Take a look at its drawing and familiarize yourself with the main elements:

The connection diagram with a bypass is good because it allows you to switch from natural circulation to forced circulation at any time. It will also help you replace the water pump without stopping and draining the entire heating system.

  • The circulation pump (1) is the main “person” in the system;
  • Shut-off valves (3) – disconnect the pump from the heating;
  • Bypass valve (4) – ensures that the coolant moves only through the pump or along both channels;
  • Dirt filter (2) – provides coarse filtration from large mechanical contaminants.

Let's see how to connect a pump to a heating boiler and what is needed for this. First, we inspect the installation site to find free space to place the bypass. At the next stage, we assemble the bypass elements, prepare the taps, nuts, drains and dirt filter. We will also need a set of keys to connect individual units, and seals.

Let's start assembling the bypass - we form a section with a water pump, screwing a dirt filter and taps to it. Next, we proceed to inspect the section of the pipe where the insertion will take place. We cut out a piece for the bypass tap, take the area with the pump, and cut holes for it. Next, we weld all the elements and only then tighten all the threaded connections with wrenches - this cannot be done before welding.

You can also install a check valve on the heating pump - it will help prevent the coolant from moving in the wrong direction.

Having connected the water pump to a floor-standing or wall-mounted boiler, we proceed to electrical work - we connect electrical wires with power to the terminals. Here it is recommended to install a separate RCD, choosing a 1 or 2 kW sample.

The next step is to start the water pump. To do this, you need to fill it with water, removing air from it. The air plug is removed through a built-in bleeder or through a plug screw. We open all the taps, open the drain or unscrew the screw plug, wait until the air comes out and water flows. After this, we seal the system and try to start the water pump. If the device is noisy, it means that not all of the air plug has come out - partially unscrew the plug screw and keep the system open until the air bubbles disappear.

Next, all that remains is to adjust the shaft rotation speed so that the productivity is slightly less than normal. There is nothing wrong with installing a water pump in a heating system with your own hands - you just need to know how to work with tools. If problems arise, consult with specialists.

Video

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.