home Heating systems How does a water pump work in a heating system? How to properly install a circulation pump in a heating system - instructions

How does a water pump work in a heating system? How to properly install a circulation pump in a heating system - instructions

The circulation pump increases the efficiency of the autonomous heating system and allows 100% use of all heating circuits.

Professional installation of a heating pump guarantees high performance, reduces operating noise and reduces maintenance and repair costs. Installing the device does not cause any particular difficulties, but there are a number of nuances that are important to consider.

We will tell you how to choose a circulation pump, help you decide on the optimal scheme for inserting equipment into the system, outline installation requirements, and also provide step-by-step instructions for installing the device.

Previously, circulation pumps were used only in centralized heating systems, and for private housing construction the natural movement of the coolant caused by temperature differences was the norm.

Now forced circulation is used everywhere thanks to the emergence of compact and inexpensive models designed to service the heating networks of small houses and cottages.

With the advent of circulation pumps, the number of circuit solutions has expanded. It became possible to lay long highways of varying complexity, while the dependence on slope practically disappeared

Due to the increase in the speed of movement of the coolant in the pipeline, thermal energy flows faster to the heating radiators, and accordingly, the rooms are warmed up faster. The load on the boiler has decreased because the water is also heated faster.

The need to install bulky and inconvenient large-diameter pipelines has disappeared; contours have become easier to camouflage under floor coverings or be buried in walls.

It has become possible to install a “warm floor” system on any floor of a private house, which operates effectively only at a certain pressure in the network

The main disadvantage of pumps for heating systems is their dependence on electricity. If the power supply is intermittent or there is a risk of a complete power outage for some period, it is necessary to install a backup power generator or at least an uninterruptible power supply.

The remaining disadvantages relate to the designs and functionality of various types of devices. For example, monoblock units and devices with a dry rotor are noisier and require constant maintenance, while a pump with a wet rotor is demanding on the quality of the coolant and has a pressure limitation.

Criteria for proper selection of equipment

All installation efforts will be reduced to zero if the equipment is selected incorrectly. In order not to make a mistake, it is necessary to first analyze all aspects of a particular heating system and make the necessary calculations.

Main types of pumps

According to their design features, all devices are divided into 2 categories: with a wet and dry rotor.

Wet pumps. This option is suitable for private homes. The unit is compact, almost silent and has a modular structure that is convenient for maintenance and repair.

But, unfortunately, it does not have high productivity - the maximum efficiency of modern models reaches 52-54%.

Circulation devices for heating networks should not be confused with similar devices for hot water supply. The heating pump does not require an anti-corrosion bronze or stainless steel housing and additional protection against scale - accordingly, it is cheaper

Dry rotor pumps productive, unpretentious to the quality of the coolant, capable of working under high pressure and do not require a strictly horizontal location on the pipe. However, they are noisier, and their operation is accompanied by vibration. Many models are installed on a foundation or metal support frame.

For installation of console, monoblock or “In-line” models it is necessary. It is advisable to use them when a flow rate of more than 100 m³/h is required, that is, for servicing groups of cottages or apartment buildings.

Brief overview of technical characteristics

When choosing a pump, you should definitely study the technical characteristics and compare them with the requirements of the heating system.

The following indicators are important:

pressure, which covers hydraulic losses in the circuit;
performance– volume of water or supply over a certain time interval;
operating coolant temperature, max and min – for modern models on average +2 ºС… +110 ºС;
power– taking into account hydraulic losses, mechanical power prevails over useful power.

Structural details are also important, for example, the inlet/outlet diameter of the pipes. For heating systems, the average parameters are 25 mm and 32 mm.

The number of electric pumps is selected based on the length of the heating main. If the total length of the circuits is up to 80 m, one device is sufficient; if more, additional devices will be required

An example of a unit for equipping a residential heating network with an area of 100 m² is a pump Grundfos UPS with a 32 mm pipe connection, a capacity of 62 l/s and a weight of 3.65 kg. The compact and low-noise cast iron device is inaudible even behind a thin partition, and its power is sufficient to transport liquid to the 2nd floor.

Pumps with built-in electronics allow you to quickly switch equipment to a more convenient mode depending on changes in temperature or pressure in the network. Automatic devices are equipped with digital displays that provide maximum information on the operation of the pump: temperature, resistance, pressure, etc.

Additional information on the calculation and selection of a circulation pump for heating is presented in the articles:

Requirements for installation of a circulation pump

There are a number of standards that regulate at the legislative level the installation of a circulation pump in a heating system. Some of the rules are set out in SNiP 2.04.05 “Heating...”. For example, it talks about priority in heating networks.

Almost all requirements are justified by the operating efficiency of the system as a whole and the circulation device in particular. For example, the shaft of a device with a wet rotor must be installed on the pipe strictly horizontally in level so that there are no air pockets inside and the pump parts do not wear out prematurely.

A mandatory element of the system is an expansion tank that compensates for changes in the volume of coolant during heating/cooling. Its place in a closed system is on the return line, in front of the circulation pump

A filter for dirt and abrasive particles is needed in any case, even when installing monolithic models. Filtered coolant will cause much less damage to pump parts than liquid with sand and suspended matter.

The mudguard is installed with the plug down in the direction of water movement to reduce resistance and facilitate system maintenance.

Some rules are dictated by manufacturers. For example, it was customary to install old models of certain brands exclusively on the return line, since they could not withstand high temperatures.

Now pumps have become more versatile and can be installed in any suitable location, but subject to power parameters.

Analysis of installation technology

The installation process itself is quick; to secure the housing, you need to secure two union nuts. This is very convenient for further maintenance and repair work. But before installation, it is necessary to choose the right installation location, otherwise the pump will either work intermittently or will soon fail.

Schemes for inserting a pump into the network

When choosing one of the schemes, it is necessary to take into account the type of heating system, boiler model and ease of maintenance.

Option 1. This is the most common solution: the pump is mounted on the “return”, through which the cooled coolant returns to the boiler. Warm water does not have such an aggressive effect on the parts of the device, so it lasts longer.

Modern devices can easily withstand high temperatures, but there are still experts who reject such a scheme.

In order to make life in the house as comfortable as possible during the winter, you should definitely perform such an operation as installing a circulation pump in the heating system. The procedure is not too complicated and, if necessary, can be done independently. But, of course, you will first have to select equipment that suits all parameters, and also become familiar with the technology for its installation.

Benefits of use

Systems with natural coolant circulation have a number of disadvantages. Firstly, pipes with a diameter that are too large have to be installed in the house. This is necessary to ensure that water circulates freely through them without lingering anywhere. Secondly, when installing such a system, you have to calculate the angle of inclination of the pipes. And thirdly, equipment of this type is not very convenient to use.

Installing a circulation pump in the heating system allows you to solve all these problems. When using it, pipes can be installed thin. It is not necessary to tilt in such systems; the heat is distributed evenly throughout the rooms. Such a pump can also be installed in a system with natural coolant circulation. In this case, the house will not be left without heating.

Varieties

At the moment, only two main types of circulation pumps are produced: wet-running and conventional. The first type is not very powerful, operates silently and is usually used in country houses and cottages. Most often this is single-phase equipment.

The pump into the heating system of an apartment building is made in the same way as into the network of a private small building. However, in this case, conventional equipment is used, that is, one in which the rotor and stator are separated from the volute by a waterproof membrane. Installation is carried out on the main line in a separate room - the boiler room. The fact is that such pumps operate very noisily. This is a three-phase powerful equipment that requires, among other things, periodic lubrication.

How to choose the right one

Before you begin such a procedure as installing a circulation pump in the heating system (it is quite possible to do this with your own hands, as you will soon see), you should, of course, purchase all the necessary equipment. So, if you need a pump for a private home, you should buy a single-phase model with a “wet running” rotor. Three-phase powerful pumps are suitable for an apartment building or a very large cottage.

In any case, when purchasing, you should study the technical data sheet of the model. In this case, first of all you need to pay attention to the following parameters:

Performance. This indicator is usually expressed in liters or cubic meters. It means the volume of liquid that the pump can pass through itself in an hour. In order to choose the right model, you should know how much water is pumped into the system. The performance value should exceed this figure by approximately three times.
Pressure This parameter shows with what force the pump can draw in coolant. The device should easily cope with pumping water along all heating curves, if necessary, lift it to the upper floors, etc. For example, for an apartment building you will need to purchase equipment with a pressure of about 20 m. For a cottage, a less powerful model is also suitable.

Circulation pumps with automation are considered very convenient to use. This model can be set on a timer, and it will turn itself off and on when necessary.

Basic installation rules

Most often, a circulation pump is installed in a heating system through a bypass pipe called a bypass. In this case, when there is a power outage, the system switches to natural circulation without any problems. In order to let water flow directly, you just need to close the bypass valves.

The circulation pump is installed only on the return pipe between the last radiator and the heating boiler. This is due to the fact that the pump does not push water, but sucks it in. In addition, under the influence of very hot coolant in the supply pipe, its mechanisms quickly fail.

Only a pressure gauge, thermometer and pressure relief valve are installed between the pump and the boiler. A filter is mounted directly next to it on the bypass. In any heating system there is a lot of different debris: scale, silt, etc. Without a filter, the pump impeller will quickly clog, as a result of which it will simply fail.

When performing an operation such as installing a circulation pump in the heating system of a private home, be sure to follow these recommendations:

If the connection is made into an already existing network, the water must first be drained from the mains. The pipeline must be thoroughly flushed.
After completing the full installation cycle, the system is filled with water again.
All connections must be sealed with sealant.
The final step is to open the central screw on the pump housing and release excess air from it.

How to install

Do-it-yourself installation of a circulation pump in a heating system is carried out as follows:

A piece is cut out in the intended section of the return pipe, the length of which should be equal to the width of the bypass.
Tees are installed on both free ends.
These elements are connected by a piece of pipe with a valve built into it.
Each tee is connected to an L-shaped piece of pipe with nuts at the end and valves.
A filter is installed on one of the L-shaped pieces (between the valve and the pump).
The nuts are screwed to the pipes of the circulation pump.

The device should be installed in such a way that the coolant subsequently moves in the direction indicated by the arrow marked on the body. In addition, the place for its insertion should be chosen in such a way that access to it is not difficult later.

How to connect to the mains

When using the method described above for installing the circulation pump, its shaft will be located in a horizontal position. In this case, air will not accumulate in it, preventing lubrication of the bearings. Among other things, when installing the device, be sure to ensure that it is located on top.

Connect the electric pump to the electrical network in compliance with all required safety rules. The power cable must be equipped with a plug or switch. The minimum distance between the axes of the contacts is 3 mm. Cable cross-section - no less than 0.75 mm. Of course, the pump must be connected to a grounded outlet.

One or more?

Typically, in a private home, only one circulation pump is installed in the heating system. The power of modern equipment of this type is quite enough to ensure a sufficient flow rate of the coolant. Two pumps are included in the system only if the total length of the pipes exceeds 80 m.

Is it possible to install without bypass?

A circulation pump is usually installed on the bypass pipe in an open-type heating system. At the same time, if necessary, the owners of a country house have the opportunity to switch the network to natural coolant current. If the system is designed without slopes, the pump can be installed in a pipe without a bypass. In this case, the installation is carried out directly into the return line. In this case, shut-off valves must also be installed. This will allow you to easily remove the device for repair or replacement without having to drain the water from the system.

A procedure such as installing a circulation pump in a heating system without a bypass is usually performed only if the house has an alternative source of electricity. This could be, for example, a modern gasoline or diesel generator. In this case, in the event of a sudden power outage, the building will not be left without heating.

How to install on polypropylene

Now let's see how the circulation pump is installed in the heating system in this case. Polypropylene is a material that is quite light and easy to work with. In this case, connect the equipment like this:

Special connections (3/4) are soldered to the ends of the line.
Next, taps are attached to them using flax.
Then the latter are connected to the pump assembly using clamps.

Operating rules

Modern circulation pumps are reliable and have a long service life. But, of course, sometimes this equipment also fails. Such a nuisance can happen, for example, due to:

too much or too little water supply,
operation without coolant in the system,
in case of prolonged downtime,
when the water is heated too much (over +65 degrees).

How to dismantle

So, we have looked at how to install a circulation pump in a closed and open heating system. Now let's discuss how to remove this equipment in case it needs to be repaired or replaced. This procedure consists of just a few steps:

the pump is de-energized,
the valves on the bypass are closed,
the valve on the main line opens,
the fastening nuts are unscrewed.

If the pump has been installed in the system for a long time, it will most likely be stuck. Therefore, you will have to knock it out by tapping it with a mallet.

It is unlikely that you can repair the pump yourself if the owner of the house does not have sufficient experience in this matter. Most likely, you will have to take it to a repair shop. But most often, owners of country buildings still install new equipment into the system; fortunately, pumps today are not too expensive.

The movement of coolant in heating systems with natural circulation is determined by the difference in density of heated and cooled liquids. The operation of heating circuits with forced movement of the thermal agent is ensured by a circulation pump. This unit solves the problem of uniform heat distribution throughout the house, so its installation is recommended in a gravity heating system, since its connection increases efficiency and efficiency. The performance and thermal efficiency of the heating branches depends on how correctly the circulation pump is selected and installed, so it is important to follow the recommendations of the equipment manufacturer and adhere to the installation rules.

Advantages of heating systems with forced circulation of coolant

Correct installation of a circulation pump in a heating system has many nuances

The use of circulation pumps in heating systems of any type provides comfortable heat, regardless of the number of floors and size of the home. This heat supply scheme has a number of advantages compared to the gravity-type model:

cost savings when installing heating associated with the possibility of using inexpensive polypropylene or metal-plastic pipes of smaller diameter;
uniform heating of all circuits and components of the heating system helps to increase the service life of the equipment;
reducing the thermal inertia of the system;
the ability to quickly change the temperature both in all heating branches and in individual areas;
reduction of energy costs.

The disadvantages of forced circulation of the coolant include noise from the operating unit, additional energy costs, as well as the inoperability of the heating system when the power supply is turned off.

Criteria for choosing a circulation pump

Correct selection of a pump (vertical, block, etc.) implies that its technical characteristics match the required pressure and performance. The first parameter affects the strength of the coolant flow, and, therefore, whether the liquid can overcome the hydraulic resistance in the heating circuits. The second indicator determines how much coolant can flow into the main line per unit of time, which affects the total power of the heating system. Choosing a circulation unit “at random” is not allowed, since a low-power pump will not pump the coolant in the required volume, and an overly strong motor increases wear on the equipment and increases the noise of the system. You can learn about all the nuances of choosing pumping equipment and the methodology for calculating its technical parameters.

How to install it yourself

Experts distinguish between two heating schemes with forced circulation of the thermal agent - one-pipe and two-pipe. The choice of one or another option determines not only the principle of circuit routing, but also the length of the pipelines, as well as the type and quantity of shut-off, regulating and monitoring equipment.

Diagram of a single-pipe system with a circulation pump

A single-pipe heating system is characterized by the sequential inclusion of heating radiators in the circuit. The coolant returns through a separate pipeline to the boiler only after it has passed through all the devices of the heating system in turn. The disadvantage of this method is that the radiators closest to the heating unit warm up more than those further away, and this reduces the thermal efficiency and service life of the equipment. By introducing a circulation pump into the circuit, the temperature is equalized at all points of the system.

Scheme of a two-pipe heating system

Two-pipe wiring has advantages over single-pipe wiring, since all heating devices are connected to the supply and return lines in parallel, which promotes uniform temperature distribution throughout all rooms. By using forced circulation of the coolant, we achieve an increase in the efficiency of the heating system and the ability to adjust its thermal power.

Determining the location of the pump insertion into the pipeline

In autonomous heating systems, sealed-type circulation pumps with a “wet” rotor are most often installed. The design features of such units allow them to operate without additional lubrication, since its role is played by the coolant. It also provides cooling for the running electric motor of the pump. Thanks to the operation of the pump rotor in a wet environment, there is no need for additional sealing, which contributes to high reliability and long service life of the units.

The pump's design with a wet rotor ensures its reliability and durability.

The design features of the circulation pumps of the first models forced the installation of equipment on the return branch of the main line, since it was believed that cooled water increases the service life of the devices. Modern units are made from heat-resistant materials, so installation is carried out both on the supply pipeline and on the return line.

Where to install pumping equipment? Manufacturers recommend doing this in the supply area near the expansion tank connection point. This increases the suction pressure and improves the heat transfer of the equipment. When deciding on such an installation scheme, you must make sure of the required thermal resistance of the selected pump. Otherwise, the device is mounted on the return section of the circuit, next to the heating boiler. The same option is recommended when installing a circulation pump when operating in conjunction with a solid fuel unit.

Equipment installation requirements

In a system with a circulation pump, a closed expansion tank must be installed

For long-term and reliable operation of the forced coolant supply system, it is necessary to correctly install the circulation pump and its piping elements.

An expansion tank must be installed in the system, which is connected to the return pipeline.
In order to prevent the formation of air pockets inside the pump, its motor shaft must be positioned in a horizontal plane. Otherwise, cooling and lubrication of the moving parts of the unit may deteriorate, as a result of which it may fail.
It is imperative to install a coarse filter in front of the pump. Its use helps to increase the service life of equipment by filtering the coolant from abrasive particles that inevitably appear during operation of the heating system.

When installing a mud filter with your own hands, be sure to observe the direction of movement of the liquid. It is recommended to install the protective element with the plug facing down. This way it will not create additional resistance to the movement of the coolant, and in addition, it will be easier to clean it from dirt.

The use of a coarse filter will save the pump blades from premature wear

Features of installing a pump in a system with natural coolant circulation

In order to ensure the operation of the heating during a power outage, it is necessary to create a minimum hydraulic resistance in all sections of the circuit. The normal movement of the thermal agent is hampered by any turns and height differences in the pipeline, the resistance of shut-off equipment and a decrease in the cross-section of the pipeline. Therefore, when installing the circulation pump, the following requirements are observed:

the insertion is performed without opening the main circuit, in parallel to it. The required pipeline diameter must be at least 32 mm, and the cross-section of the pipes for connecting the pump must be a quarter smaller;
Shut-off valves are installed before and after the pump so that if the equipment malfunctions, it can be dismantled without the need to discharge the coolant;
In the area between the pump taps, a ball valve is mounted, which is closed during the forced supply of coolant. Otherwise, it will circulate in a small circle between the pump insertion points.

Correct placement of the circulation pump piping elements

A check valve installed instead of a ball valve will help automate the switching process in the absence of electricity. The so-called bypass will be closed until the pump turns off and the pressure in front of the valve does not exceed the force of the operating spring.

The disadvantage of spring check valves is the additional resistance to fluid flow, so the best solution would be to install a ball-type device.

By installing a check valve you can automate the bypass operation

Installation and connection instructions

To install the circulation unit correctly, it is necessary to follow a number of rules and strictly follow the sequence of operations.

At the very first stage, bypass sections are inserted to connect the pump. In the future, this will make it possible not to overheat the plastic inserts of the ball valves during welding work.
On the section of the main pipeline between the tie-ins, a bypass is installed, equipped with a ball valve or check valve.
Shut-off valves are installed on the bypass main.
A coarse filter is installed.
The upper part of the bypass is equipped with an automatic air valve or Mayevsky tap.
In accordance with the direction of movement of the coolant, a circulation pump is installed. The rotor of a “wet” unit is mounted strictly horizontally, with the contacts in its terminal box facing upward.
The pump is connected to the electrical network through a separate outlet with grounding.

Bypass assembly

All threaded connections must be sealed. The best material is plumbing linen and a special paste, which allow you to accurately set the relative position of the parts without the risk of leaks in the future.

The industry produces ready-made kits for installing circulation pumps, including parts of pipelines, shut-off and connecting elements.

How to start the pump

Before starting the circulation pump after a long period of inactivity, it is necessary to remove air from its working cavity

After installing the equipment, the heating system is filled with water, and then the boiler is turned on. To remove air from the working cavity of the pump, it is necessary to unscrew the plug located on the front cover of its housing. The complete “de-airing” of the unit is indicated by the flow of liquid without bubbles. Additionally, it is necessary to remove air pockets from all areas of the system. And only after this can the supply voltage be applied.

It is possible that after a long period of inactivity the pump will not be able to start on its own. In this case, unscrew the protective plug and use a flat blade screwdriver to turn the rotor shaft of the unit, for which a special slot is made on the end surface of the part. After the pump has been running for five minutes, the air removal process is repeated.

Please note that the “de-airing” procedure is carried out every time after a long period of equipment downtime.

You can avoid the harmful effects of air locks by installing equipment equipped with an automatic system for protecting and monitoring its operation.

Installation of a circulation pump (video)

By installing a centrifugal pump, you can increase the efficiency and improve the efficiency of the heating system. In addition, it becomes possible to accurately distribute thermal energy between all rooms, which creates a cozy atmosphere in the house.

Circulation pumps are installed in heating systems with forced or natural circulation. It is needed to increase heat transfer and to be able to regulate the temperature in the room. Installing a circulation pump is not the most difficult task; if you have a minimum of skills, you can do it yourself, with your own hands.

What is a circulation pump and why is it needed?

A circulation pump is a device that changes the speed of movement of a liquid medium without changing pressure. In heating systems it is installed for more efficient heating. In systems with forced circulation it is a mandatory element, in gravity systems it can be installed if it is necessary to increase the thermal power. Installing a circulation pump with several speeds makes it possible to change the amount of heat transferred depending on the outside temperature, thus maintaining a stable temperature in the room.

Cross-section of a circulation pump with a wet rotor

There are two types of such units - with a dry and wet rotor. Devices with a dry rotor have a high efficiency (about 80%), but are very noisy and require regular maintenance. Units with a wet rotor operate almost silently; with normal coolant quality, they can pump water without failure for more than 10 years. They have a lower efficiency (about 50%), but their characteristics are more than sufficient for heating any private home.

Where to put

It is recommended to install a circulation pump after the boiler, before the first branch, but on the supply or return pipeline it doesn’t matter. Modern units are made from materials that can withstand temperatures up to 100-115°C. There are few heating systems that work with a hotter coolant, so considerations of a more “comfortable” temperature are untenable, but if you feel safer, put it in the return line.

There is no difference in hydraulics - the boiler, and the rest of the system; it makes absolutely no difference whether there is a pump in the supply or return branch. What matters is the correct installation, in the sense of strapping, and the correct orientation of the rotor in space. Nothing else matters.

There is one important point regarding the installation location. If the heating system has two separate branches - on the right and left wings of the house or on the first and second floor - it makes sense to install a separate unit on each, and not one common one - directly after the boiler. Moreover, the same rule remains on these branches: immediately after the boiler, before the first branch in this heating circuit. This will make it possible to set the required thermal conditions in each part of the house independently of the other, and also in two-story houses to save on heating. How? Due to the fact that the second floor is usually much warmer than the first floor and much less heat is required there. If there are two pumps in the branch that goes up, the speed of movement of the coolant is set much lower, and this allows you to burn less fuel, without compromising the comfort of living.

Harness

There are two types of heating systems - forced and natural circulation. Systems with forced circulation cannot work without a pump; systems with natural circulation work, but in this mode they have lower heat transfer. However, less heat is still much better than no heat at all, so in areas where electricity is often cut off, the system is designed as hydraulic (with natural circulation), and then a pump is installed into it. This gives high heating efficiency and reliability. It is clear that the installation of a circulation pump in these systems is different.

All heating systems with heated floors are forced - without a pump, the coolant will not pass through such large circuits

Forced circulation

Since a forced circulation heating system without a pump is inoperative, it is installed directly into the gap in the supply or return pipe (of your choice).

Most problems with the circulation pump arise due to the presence of mechanical impurities (sand, other abrasive particles) in the coolant. They can jam the impeller and stop the motor. Therefore, a mesh dirt filter must be placed in front of the unit.

Installing a circulation pump in a forced circulation system

It is also advisable to install ball valves on both sides. They will make it possible to replace or repair the device without draining the coolant from the system. Turn off the taps and remove the unit. Only that part of the water that was directly in this piece of the system is drained.

Natural circulation

The piping of the circulation pump in gravity systems has one significant difference - a bypass is required. This is a jumper that makes the system operational when the pump is not working. One ball shut-off valve is installed on the bypass, which is closed the entire time the pumping is running. In this mode, the system operates as forced.

When the electricity goes out or the unit fails, the valve on the jumper is opened, the valve leading to the pump is closed, and the system operates as a gravity system.

Installation features

There is one important point, without which the installation of the circulation pump will require rework: it is necessary to rotate the rotor so that it is directed horizontally. The second point is the direction of flow. There is an arrow on the body indicating which direction the coolant should flow. This is how you turn the unit so that the direction of movement of the coolant is “in the direction of the arrow”.

The pump itself can be installed both horizontally and vertically, just when selecting a model, make sure that it can work in both positions. And one more point: with a vertical arrangement, the power (pressure created) drops by about 30%. This must be taken into account when choosing a model.

Power connection

The circulation pumps operate from a 220 V network. The connection is standard; a separate power supply line with a circuit breaker is desirable. The connection requires three wires - phase, neutral and ground.

The connection to the network itself can be organized using a three-pin socket and plug. This connection method is used if the pump comes with a connected power wire. It can also be connected via a terminal block or directly with a cable to the terminals.

The terminals are located under a plastic cover. We remove it by unscrewing several bolts and find three connectors. They are usually labeled (the pictograms are N - neutral wire, L - phase, and “ground” has an international designation), so it’s hard to make a mistake.

Since the entire system depends on the performance of the circulation pump, it makes sense to make a backup power supply - install a stabilizer with connected batteries. With such a power supply system, everything will work for several days, since the pump itself and the boiler automation “pulls” electricity to a maximum of 250-300 W. But when organizing, you need to calculate everything and select the battery capacity. The disadvantage of such a system is the need to ensure that the batteries do not discharge.

The basic rule for creating any heating main is: the longer the line, the worse the water circulation in the system. For this reason, problems arise with uneven heating of rooms. The simplest and most convenient way is to install a pump in the heating system of a private home.

Why connect the pump?

Gravity heating is based on the principle of communicating vessels: water in the upper reservoir is heated by a gas burner and begins to flow through the pipes, passes through all the batteries and returns to the lower reservoir, from which it again enters the heating chamber. Using a natural circulation system, it is necessary to ensure a height difference sufficient for good coolant flow.

In practice, this is extremely difficult to do, so heating with natural circulation is characterized by a small heating area, a maximum of 60-80 m². For large, and even more so 2 or 3-story houses, you will definitely need to install a water circulation pump. This will ensure uniform distribution of the coolant along the entire length of the heating system.

In addition, due to the installation of the pump, fuel consumption is reduced. Water passes through the system faster, therefore, it does not have time to cool down too much and less thermal energy is required to reheat it.

An alternative option is to install larger diameter pipes. But in this case, the total cost of materials and work will be much higher, in addition, for houses with an area of more than 200 m², this still will not completely solve the problem.

How to choose a circulation pump?

During the cold season, the device operates 24/7. Low-quality options will not withstand the load and will quickly become unusable. To avoid this, you need to know the selection criteria:

pipe diameter;
boiler throughput;
water temperature;
total displacement of the system.

The pressure in the system depends on the diameter. Therefore, you need to know how many atmospheres the pump is designed for. It is better to buy with a reserve; at the time of the first start-up of the system and bleeding of air, water hammers are possible - short-term periods of increased pressure. If the device is picked up end to end, it will break. In addition, the inlet and outlet pipes of the pump must match the diameter of the system. Otherwise, you will have to purchase adapters and other fittings.

Some boilers heat 2-5 liters per minute, others - 10-20 liters. In order for the device to cope with the volumes, it must have the appropriate throughput, otherwise the pump will not cope and the device will fail.

Manufacturers make products using various technologies; the cheaper the pump, the lower the quality of the spare parts. Individual units are not always designed for temperatures above +60-70°C. In regions with cold winters, where the coolant is supplied at a temperature of +75-85°C, this fact must be taken into account.

One of the main elements of the circulation pump is the motor. When choosing a device, you need to understand how many liters will be pumped per cycle. The service life of the motor must be selected with a reserve; in addition, it is better to install a device that has built-in protection against overheating.

Types of pumps

There are 2 types of pumps used in heating systems:

dry;
wet.

The first option is large industrial pumps, which are used for heating systems of large plants, factories or apartment buildings. They are noisy, take up a lot of space and are more expensive than their counterparts. The main advantage is high power. It is recommended to install only for objects such as private hotels and boarding houses.

Wet pumps are designed specifically for insertion into a heating system. They work directly in the aquatic environment, so all components are resistant to corrosion and moisture.

The motor and other electrical parts are insulated with rubber gaskets. Therefore, when choosing a device, it is not recommended to purchase models from the market. They could have been in the sun for a long time, respectively, the rubber would have dried out and the device would burn out in 2-3 months, since water would flood the motor.

Choosing a place to install the pump

How to properly install a pump in a heating system? The main thing is to choose a suitable place. Basic instructions are included with the device. In addition, there are general recommendations:

Make connections to the system in places where there is easy access to the pump. There should be plenty of free space around so that diagnostics or repairs do not cause problems.
The direction of water supply does not matter much, but it is better to install the pump on a hot branch. This will ensure uniform distribution of the coolant throughout the heating system.
Most often, the pump is placed near the expansion tank. This is convenient and practical, since it is possible to check both components at once and, if necessary, carry out repairs or replace parts. When figuring out where to install the pump, you also need to remember that the device is noisy during operation. Therefore, the place should be located away from living rooms.

Tools and Supplies

Correctly connecting the pump involves preliminary preparation of the necessary equipment. To work you will need:

2 water pipes or 2 Swedish wrenches of the appropriate diameter;
fum tape 10 mm;
3 ball valves;
2 tees.

The basic set may vary depending on the type of pipes used.

For efficient heat distribution, it is better to connect the circulation pump before the start of the heating season. In this case, you can immediately check how effectively it works.

Circulation pump installation steps

The procedure is simple and consists of 3 steps:

inset;
connection;
examination.

Let's consider options for installing the pump on metal or plastic pipes. These options are different from each other.

Insertion into a metal pipe

To save time and do everything right right away, you need to:

Check the system for the presence of water and, if necessary, drain the remaining water.
Select the part of the pipe where the unit will be installed.
Mark points on the pipe for insertion of pump pipes.
Weld in 2 threaded pipes.

The first point is mandatory; if water flows into the welding process, there will be big problems, since the seams will not set correctly.

At the second stage, you need to check the selected section of the pipe for strength and inspect it so that rust does not appear. If everything is in order with this, markings are made according to the formula pump length plus 10-15 cm.

All that remains is to drill holes in the pipe and weld the pipes. Tap the seam with a hammer to knock off scale and check the strength of the structure. During the welding process, the welded pipes must be strong; make sure that the thickness of the seam is the same along the entire radius. The pump does not literally crash into the heating system, but is screwed to the pipes with special fittings. Before twisting, you need to wrap the thread with fuma.

Connection to a plastic pipe

The connection diagram for the circulation pump differs only in the absence of welding, first the tee, then the pipe. For maximum reliability, it is recommended to use the pipe soldering method. This will remove elements susceptible to corrosion from the structure. In addition, if metal nuts are overtightened, they often develop microcracks through which water then leaks.

Also, for both schemes it is necessary to install an additional ball valve in the area between the nozzles. This is done so that it is always possible to redirect water from the pump directly into the system. Accordingly, the device can be removed for repair or replaced without shutting down the entire heating system.

Installation of ball valves on a branch pipe

When installing taps, first install only the side that goes into the pipe, always onto the thread. For metal pipes there will be no problem if the diameter of the tap is different, just screw on the adapter. For plastic pipes you need to use special fittings.

They are either soldered to the pipe through a connector and an additional pipe with an assembled fitting, or fixed directly into the pipe using special clamping nuts. The second method is less reliable.

Let's take a closer look at why a crane is needed. If, even after installing the pump, the heat is distributed unevenly, or problems appear during operation, it means that the pump cannot cope with pumping.

Accordingly, you need to remove the pump and carry out diagnostics. If you do not install shut-off valves, this will not be possible, since you will have to stop the boiler and drain all the water. If there are taps, it is enough to turn them off, and the water will flow along the old branch, and the pump will be suitable for dismantling.

Pump installation

When the pipes are installed, all that remains is to screw the pump to the taps. To do this, wrap the threads with foam and tighten the nuts. Often the corners are included. Therefore, they are immediately screwed to the pump. If there are no components in the box, you need to separately purchase corners of the appropriate diameter and screw them to the inlet and outlet pipes.

It is not recommended to overtighten the nuts to prevent them from bursting. It is better to wait until it starts and check for leaks. You can tighten the fastenings later. You can use any scheme for installing a circulation pump in a heating system, but you must strictly follow the basic principles and follow the sequence of actions.

Starting the system

After all installation work has been completed, the resulting structure must be checked. In this case, the system starts first without a pump. This is a mandatory condition, otherwise water hammers will begin to occur in the pipes, which, at best, will damage the connections in the pipes, and at worst, will rupture one or more batteries.

Air penetrates into the pipes of an open heating system; it can circulate along the entire length of the pipeline and fill the voids. This leads to the appearance of plugs that interfere with the normal passage of water. To get rid of the problem, you need to bleed the air and only then start the pump.

Then you can move on to testing.

The procedure is done like this:

Turn off the valve on the supply line.
Open the tap on the supply pipe and wait 30-40 seconds for water to fill the pump.
Open the tap on the outlet pipe.
Turn on your device.

An important point is that the temperature of the coolant must be increased gradually. When heated, all bodies expand; if you immediately put boiling water into the system, the connections will not have time to smoothly open and leaks will appear. To avoid this, increase the water temperature from +40 to +70°C gradually.

up to 100 m² - by 5° every 10 minutes;
up to 200 m² - by 5° every 30 minutes;
300 m² or more - by 10° every hour.

This will allow the entire line to be heated evenly.

System check

For normal water circulation, the heating system needs to warm up. It takes 2-3 hours. Wait the specified time and check each battery by touch, they should all be at the same temperature.

If you find a hotter or colder one, try deflating. For overheated batteries, you need to bleed them in a subsequent radiator, for cold ones - in the previous one. Most likely, the problem will be resolved.

Another possible reason is a leak. Carefully inspect the connection points between the batteries and the pipe. Even if there are no obvious puddles, water may appear at the joints. Recheck the connection and the problem will go away.

The last uncharacteristic point is extraneous noise in the pump. In new models, this problem only occurs if foreign objects, rust or other debris gets into the pump. To avoid this, it is recommended to install a filter on the supply pipe. Eliminated by disassembling and cleaning the pump.

Installing the pump is easy; the procedure takes from 30 minutes to an hour. Starting up the system will take longer, but will also not cause any particular difficulties, but several operational issues remain:

The first thing you need to pay attention to is the position of the pump relative to the horizon. A prerequisite for the device to serve for a long time is that the motor shaft must be located either at an angle of 90° or 180°. Any misalignment will cause the bearings to wear out 2-5 times faster.
The main disadvantage of a circulation pump is that it does not work without electricity. If the owners are at home, it is not difficult to come and turn off the tap, but if they are not there, the house will not be heated.

To solve this problem, it is recommended to use ball valves with a check valve. The device works in this way: water is supplied to the pump as long as the pressure at the inlet and outlet is the same. If the outlet pressure drops, the valve switches the water supply to the gravity main.

This method will not provide the same high-quality circulation of coolant in the system, but the house will still be heated. During the day, the lack of heat will not cause much harm, but if the lights are turned off during vacation, and the owners were not home for 5-10 days, the water in the pipes will freeze and they will burst.

Don't forget to clean the mudguards. Metal pipes contain a lot of rust and salt deposits. The speed of water circulation after turning on the pump will increase by 1.5-3 times, accordingly, all the dirt will go straight into the pump. When first starting out, it is recommended to clean it once a week.

If after the specified time the filter is clean, it means that most of the debris has already been washed away. And the procedure can be repeated 2 times a year: after stopping the system for the summer and a week after starting.

Bearings wear out in 3-4 years in operating mode 6 through 6. If the pump operates in northern temperatures, 8-9 months a year, its service life will last for a maximum of 2 years. A sure sign that it is time to change the bearings is the appearance of noise in the pump. This happens because the shaft begins to rotate with play, resulting in increased load on the housing and all parts.

To avoid damage to the entire pump, it is enough to disassemble it and replace the bearing rings. These components are inexpensive, and the work itself takes 20-30 minutes. Remember, the device should operate without diagnostics for no more than 2 years, this will avoid costly repairs.

Powerful boilers quickly heat water, but due to the diameter of the pipes, it takes a long time for it to reach the radiators by gravity. The pump solves this problem if it is connected to the supply line. On the other hand, hot water negatively affects most components, so the device breaks down faster.

When there is no goal to warm up the house as quickly as possible, and the main emphasis is on durability, it is recommended to install the pump on the cold water line. In practice, this will extend the life of the device by 2-3 years.

Using these simple recommendations, you can maximize the life of your device. A pump for the heating system of a private home is a convenient and practical thing; if there are problems with heat distribution, there is no need to think twice. Determine the system parameters and buy the appropriate model.