Where should the pump be located in the heating system. Scheme of installing a pump in the heating system of a private house

Gone are the days when water heating systems worked without pumps. And today, the efficiency of the heating system is increased precisely due to the installation of the pump. In addition, the room warms up much faster and fuel consumption is reduced. Connecting the pump to the heating system makes it possible to mount towel dryers, thermostats and use pipes of smaller diameter.

Advantages of connecting the pump to the heating system

The owners of country houses with a decentralized water supply system are faced with the problem of uniform distribution of heat throughout all heating circuits. For example, if water boils in the boiler, and radiators in distant rooms remain barely warm. In this case, it is recommended to look for the best means to solve the problem.

To improve circulation, there are two proposals: installing large diameter pipes or updating the system by installing, or rather tapping into the pipe, a pressure pump. There are few people who want to take up the dismantling of pipes, if at the same time they are still walled up indoors. And the cost of the system itself, which includes pipes with a large diameter, is not always liked by the owners because of its high cost. And the price of the pump for the heating system is much lower.

Therefore, it becomes necessary to install a pressure pump. Circulation pumping devices are installed on heating systems operating on all types of fuel - wood, coal, fuel oil. Updating the heating system by inserting a pump into the heating system will help you:

• To equalize the temperature in the pipes;
• Eliminate the appearance of air pockets that prevent the coolant from circulating normally;
• Make an increase in the area of ​​​​action of your heating system.

Rules for choosing a pump for a heating system

For installation in a heating system, it makes no sense to purchase a fairly powerful pump, because you will not use it at full capacity. Also, it will make loud noises. The owner who buys the pump is advised to remember that the power of the device should be 10% higher than the value that was obtained as a result of your calculations.

The ability of pumping equipment to meet the needs of the heating system depends on many parameters. For example, on the diameter of pipes, maximum pressure, water temperature, coolant density:

1. The flow rate of the coolant Q, which passes through any section of the thermal system, is calculated in the same way as the fluid flow rate for boiler equipment. That is, equate the value of the coolant flow rate to the boiler power parameters. With a boiler power of 20 kW per minute, about 20 liters pass through it.
2. Radiators with a power of 10 kW will pass 10 liters per minute. When calculating the water flow in each ring of the heating system, take into account the power of the batteries.
3. The fluid flow in the pipes is determined by the diameter of the pipelines. The smaller the diameter, the more resistance will occur in the path of the coolant.

The longer the pipeline, the more powerful the pressure pump for the heating system should be. This suggests that for every 10 meters of the heating system, 0.6 meters of pressure are needed from the pump. To ensure the productive operation of the ring at 100m, a pump head of 6m is required.

Classification of pumps for the heating system

Two types of pumps are used to move the energy carrier in the heating system:

• dry pumps. The rotor in such equipment does not come into direct contact with the energy carrier. When considering such equipment as an installation in a heating system, pay attention to some of its features. The power plant of the pump with the so-called "dry" rotor does not come into contact with the energy carrier during operation. The seal, located in the unit, is necessary for hermetic separation of the pump from the motor. The main advantage of such pumps is high efficiency - about 80%. Therefore, their use is advisable when constantly pumping a large volume of water. The equipment is used primarily for large commercial premises, factories, factories and multi-storey buildings. Due to the rather strong noise that is generated during operation, such pumps are not suitable for private homes.
• Wet pumps. Their working part is in the water they pump. With the help of water, the engine is cooled, and all its components are lubricated. Electricity flows through the stator. Thus, it is well protected from the impact of the coolant by a stainless non-magnetic glass. The main advantages of pumping pumps with a rotor in water: long service life, infrequent service, low noise, compactness and low weight, easily replaceable blocks, installation of the pump in the heating system is carried out directly on the pipes. Of course, among all the pluses there is a minus. Such devices demonstrate a rather low efficiency, which is 30-50%. A pressure pump with such a rotor is usually used in heating systems of houses and city apartments. It must also be remembered that pumps should not be used for drinking water supply and food related tasks.

Pump installation technology in the heating system

Preparatory work

For installation in a heating system, it is recommended to buy pumping equipment, which includes detachable threads. If there are no such parts, you need to buy yourself. Don't forget the deep filter. You should also prepare a check valve to ensure the normal operation of the heating system.

After selecting a pump for a heating system, it is recommended to purchase a set of special keys for its installation, valves, a small piece of pipe. Its diameter should be the same as the diameter of the riser.

Choosing a location for the pump

When connecting the heating pump, choose such a scheme so that you can periodically service the system. It is desirable that you have an approach to it. If in earlier models of “wet” pumps, some parts could fail due to contact with water, now systems are produced in such a way that they are not at all afraid of water. Even at different high and low temperatures. This makes it possible to install pumping equipment on the return or supply pipeline.

To increase the pressure in the discharge section, it is necessary to install a pump near the place where the tank is connected in the section of the falling pipeline. Such a scheme makes it possible to create high temperatures in this area of ​​\u200b\u200bheating. Before installing the pump in the heating system on the bypass pipe, check that the unit can withstand a strong pressure of high temperature water.

For more efficient operation of the "warm floor" equipment, the pumping unit is placed at the site of the supply of heated water. Thanks to this, such a problem as the occurrence of air congestion will be eliminated. To restore the heating system with a membrane tank, put the bypass with the pumping unit on the return line. It is advisable to bring it closer to the expansion tank.

Pump installation rules

Proper installation of the pump in the heating system requires compliance with several rules:

• Install ball valves on both sides of the pumping equipment. They are required to ensure that the pump is dismantled if it becomes necessary to service or repair it.
• In the heating system, a filter is usually installed in front of the pump, which cleans the water from mechanical debris coming with the coolant.
• To remove accumulated air, install a special valve at the top of the bypass, which can be automatic and manual.
• When installing the pump for flushing the heating system, the direction indicated by the arrow on the pump must be observed. Remember that the direction must match the direction of fluid movement.
• In order not to damage the “wet” pump, if suddenly the motor is not completely immersed in water, the device is mounted horizontally.
• The terminals of the pump unit must be at the top.
• In the heating system, gaskets must be installed on all threaded connections, pre-treated with sealant.
• For safe use of the pump for the heating system, connect to a socket that has a ground connection. Before installing the pump, do not forget to carry out the steps that are related to the provision of grounding.

Pump installation principles

When inserting a pump into a heating system, pay attention to the following principles:

1. First, drain the water and clean the system. Flush a heating system that has been in use for a long time several times, filling it with water and emptying it to successfully clean it of contamination.
2. Next, embed the pump into a specially designated place, according to the plan. In this case, you need to look at the direction in which the energy carrier is moving. It is usually indicated by an arrow on the pump.
3. After complete installation, filling with an energy carrier is carried out.
4. Check the system for its functionality. If there are still some errors, then at this stage you need to correct them.
5. Further, unnecessary air is removed from the system using the central screw. The correctness of the action is signaled by the outgoing water, which emerges from a special hole.
6. De-aerate the manual pump every time before turning it on. Turn on the pump for 5 minutes and open the valve. This procedure is carried out several times.
7. The pump turns on after filling the pipes with water. The system must be running. Remember that there should be no air left in the pipes.
8. In order to automate the operation of the pump and protect equipment from improper operation, buy an automatic pump. When connecting the pump to the mains, it is recommended to use an automatic fuse with a flag. It will perform two functions - a switch and a fuse. The fuse is installed at a distance of 50 centimeters or more from the boiler.
9. To install an additional pump in a heating system where there is already one, keep in mind that it turns on after the thermal relay trips. In order for both devices to work synchronously, you need to connect the second pump, also connect it to the thermal relay. Also, an additional one can be connected to the main pump by means of a parallel connection.

Now you know how to install a circulation pump, and how to equip a heating system with two pumps. When taking into account all the rules and features when performing such work, you can forget about the problems of uneven heat distribution in the system and the formation of air gaps.

For autonomous heating of a country house with natural circulation, a common problem is typical. Uneven movement of the coolant through the system leads to uneven heating of heating devices, especially if the heating system is long enough. Solves the problem of uneven movement of the coolant heat pumps heating, turning heating into a forced circulation heating system.

Why install a circulation pump

If you are faced with problems of uneven heating of the heating system around the house, there are two ways to solve it:

1. Replace all heating pipes by installing pipes of a larger diameter;
2. Or install a circulation pump in the system.

Obviously, installing a circulation pump is much cheaper and more practical than replacing pipes. By inserting a circulation pump into the system, several problems can be solved:

• Heating of heating devices will be more uniform;
• The contour of the heating system will expand significantly;
• The pump will eliminate the problem of air locks.

With a pump, it will be easier to take a shower and use other plumbing devices at home at the same time. By the way, you can always buy cheap cheap shower cabins. Moscow is full of surprises and the TM Titan online store is one of them.

It is worth noting that in order to install a circulation pump, you will not have to do complex installation work in an already finished heating system. Insertion technology is used.

Selection (calculation) of the circulation pump

To select a circulation pump, it is necessary to make its power calculation. If you have a complex heating system, it is better to entrust the calculation of the pump to a specialist. In a simple heating system, the power of the required pump is calculated by the formula:

The calculation will allow you to select the pump according to the parameter: maximum water performance or throughput.

Paying attention

Please note that the circulation pump requires the availability of electricity. Electrical power is not indicated on the pump label, but is 100-250 W, which allows you to connect them to any group of power outlets at home. However, to protect against electric shock, the pump power line must be protected by a 30 mA RCD.

Important! During operation, the circulation pumps make a fairly strong “buzzing” sound. This parameter can be indicated in the descriptions of the pump and you need to pay attention to it, the smaller it is, the better.

Installing a circulation pump in a heating system

Work material

From the materials you will need:

• The pump itself
• Connecting fittings for tie-in pump;
• Check valve or bypass valve;
• Two shut-off valves (ball valves) for installation on both sides of the pump;
• Coarse filter;
• Coupling with locknut;
• Winding and sanitary paste.

Work tool

For work, prepare the following tool:

• Adjustable and wrenches of the right size;
• Welding.

Selecting the location of the pump

A modern "wet" type circulation pump can be installed both in the return and in the direct heating branch. Traditionally, the circulation pump is placed in the "return" in front of the boiler in order to:

• Reduce wear and increase the life of the pump rotor;
• Avoid boiling of the boiler due to air being drawn out of the boiler by the pump;
• Damage to the pump due to the possible boiling of the boiler, especially solid fuel.

Scheme of the pump in the forward pipeline and Scheme of the pump in the return pipeline

Instructions to connect the circulation pump

Note: There are two options for pump tie-in: with the installation of a shut-off valve or the installation of a ball valve on the main tie-in line.

• When installing the pump in an existing heating network, first drain all the coolant;
• If necessary, clean the heating pipes;

• At the pump installation site, a bypass is mounted. The diameter of the bypass pipe must be made smaller than the diameter of the main pipe;

• We put a dirty filter in front of the pump. There is a water flow arrow on the filter. It will stop the sludge of the system;

• The pump shaft must be installed horizontally. The arrow of the coolant movement is shown on the pump housing;
• Shut-off valves (ball valves) are placed before and after the pump. They play a technical role in case of repair.;
• A shut-off valve or ball valve is placed on the main coolant pipe;

• When assembling, we adhere to the scheme;

• After the installation of the pump is completed, the system is filled with coolant. Next, the pump screw opens to bleed air (water will appear in the screw hole).

The installation of a circulation pump in dwellings with an individual heating system ensures uniform and high-quality distribution of heat throughout all the premises of the house.

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

Circulation pump

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

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

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

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

Circulation pumping unit

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

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

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

In "wet" units, the coolant itself performs the function of lubrication. The impeller and rotor of such installations are immersed in water. "Wet" devices are much less noisy, they are easier to mount with your own hands. And their maintenance is simpler compared to "dry" pumps.

The body of the "wet" installation, as a rule, is made of brass or bronze. Between the stator and the rotor there must be a special separator made of stainless steel. It is called a glass. It is necessary to give the required tightness to the engine (more precisely, its elements under electrical voltage). It is the “wet” units that are most often mounted in a private house in the heating system.

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

The key indicator that determines the efficiency of the circulation pump is its power. For a domestic heating system, you do not need to try to purchase the most powerful installation. It will only hum strongly and waste electricity.

Mounted circulation pump

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

The flow of hot water is determined simply. It is equal to the power of the heating unit. If, for example, you have 20 kW, no more than 20 liters of water will be consumed per hour. The pressure of the circulation unit for the heating system for every 10 m of pipes is about 50 cm. The longer the pipeline, the more powerful the pump must be purchased. Here you should immediately pay attention to the thickness of tubular products. The resistance to the movement of water in the system will be stronger if you install small pipes.

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

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

Installation of circulation pumps is carried out in two ways. The first connection scheme of the unit is two-pipe. This connection method is described by a high temperature difference in the system and a variable flow rate of the coolant. The second scheme is one-pipe. In this case, the temperature difference in will be insignificant, and the carrier flow rate will be constant.

Installed circulation pump

Do-it-yourself connection of the pump is carried out according to the instructions that are attached to the unit. It also indicates the installation procedure for a functional reinforcing chain. Be sure to drain all water from the system before installing the pump. Often there is a need to clean it. During the operation of the heating boiler, a lot of debris is collected on the inner surfaces of the pipes, which worsens the technical performance of the system.

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

The procedure for installing the pump itself looks like this:

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

Further, valves (shut-off) are installed at the inlet-outlet section of the circulation unit. For an open heating system, an expansion tank is additionally required (not installed in closed complexes). The final stage of installation work is the processing of all, without exception, the connection points of various elements of the system with a good sealant.

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

Professional installation of the pump for heating guarantees high performance, reduces noise and reduces maintenance and repair costs. Installation of 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 central heating systems, and for private housing construction, the natural movement of the coolant caused by the temperature difference was the norm.

Now forced circulation is used everywhere due 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 the slope has practically disappeared

Due to the increase in the speed of the coolant in the pipeline, thermal energy flows faster to the heating radiators, respectively, the premises warm up faster. The load on the boiler has decreased because the heating of water has also become faster.

The need to install bulky and inconvenient large-diameter pipelines has disappeared, it has become easier to mask the contours under the floor covering or deepen into the walls.

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

The main disadvantage of pumps for heating systems is their dependence on electricity. If the power is intermittent or there is a risk of a complete blackout 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 devices of various types. For example, monoblock units and devices with a dry rotor are noisier and require constant maintenance, while a wet rotor pump is demanding on the quality of the coolant and has a head limit.

Criteria for a competent choice of equipment

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

The main types of pumps

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

Wet pumps. This option is suitable for private houses. 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 performance - 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 need an anti-corrosion housing made of bronze or stainless steel and additional protection against scale - respectively, and is cheaper

Dry rotor pumps productive, unpretentious to the quality of the coolant, able to work 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 mounted 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.

Specifications at a Glance

When choosing a pump, be sure to study the technical specifications and compare them with the requirements of the heating system.

Important indicators are:

• pressure, which covers the loss of hydraulics in the circuit;
• performance- the volume of water or supply for a certain time interval;
• coolant operating 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 nozzles. For heating systems, the average parameters are 25 mm and 32 mm.

The number of electric pumps is selected, focusing on the length of the heating main. If the total length of the circuits is up to 80 m, one device is enough, 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 pipe connection 32 mm, capacity 62 l/s and weight 3.65 kg. A compact and low-noise cast-iron device is not audible even behind a thin partition, and its power is enough 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 the installation of a circulation pump

There are a number of norms that regulate the installation of a circulation pump in a heating system at the legislative level. 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 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 a pipe strictly horizontally in level so that air pockets do not occur inside and the pump parts do not wear out prematurely.

An obligatory element of the system is an expansion tank, which compensates for changes in the volume of the coolant during heating / cooling. Its place in a closed-type system is on the return line, in front of the circulation pump

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

The sump is installed with the stopper 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 place, but subject to power parameters.

Analysis of the installation technology

The installation process itself is fast, so to fix the case, you need to fix two union nuts. This is very convenient for further maintenance and repair work. But before installation, it is necessary to choose the installation site correctly, otherwise the pump will either work intermittently or will soon fail.

Pump tie-in schemes in 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 is not so aggressive 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 a separate heating system with natural circulation, there are some problems that can be solved with the help of a circulation pump.

Forced circulation in the heating system - why is it needed

Installing a circulation pump in the heating system will allow you to evenly distribute heat to all radiators. It is the uneven heating of the batteries that is the most common malfunction of water heating with natural circulation. There may be several reasons, and all of them lie in improper installation: insufficient pipe diameter, slopes not observed, excessive length of the system, air congestion in it.

Many people, after finding out the cause of the poor performance of the heating system, come up with the idea to redo it. And this means that you will have to change pipes, if not all, then part of them, set slopes, punch holes in the walls, and redo something. In a word: renovation. Dust, welding smoke and money, and a lot of it. Is there no other way out? There is, and it costs less, the work is done faster, no dust. Of course, we are talking about the circulation pump.

If the heating performs its functions normally, does it make sense to install a forced coolant supply? Definitely yes, and here's why:

1. 1. The inertia of the heating system is noticeably reduced. The circulation of water under duress dramatically reduces the time from ignition of the boiler to warming up even the most remote batteries.
2. 2. The temperature in all batteries will equalize. During natural circulation, the coolant has time to cool down before it returns to the boiler; nearby radiators warm up better than distant ones.
3. 3. The pressure in the system will increase. Air locks will not interfere with the normal circulation of the coolant.

We get acquainted with the unit - how it is arranged and works

The circulation apparatus makes warm water move along a closed heating stake. Its device is simple: a rotor with an impeller is installed on a stainless body. They rotate when the electric motor is running, the impeller draws water in and squeezes it out into the system from the other side. Centrifugal force creates a pressure that overcomes the resistance of the entire system.

Heating pumps are produced in two types: dry and wet. In dry ones, the rotor does not have contact with the coolant, their efficiency reaches 80%. It is very noisy, so a separate room with good sound insulation is required. Dry pumps require constant maintenance. It is necessary to constantly remove dust from the room, otherwise it may be drawn into the apparatus, and it will depressurize. Dry pumps also need to be constantly lubricated.

Despite the low efficiency of a wet circulation pump compared to a dry one - only 5% versus 80% - they are used much more often in everyday life. This is due to lower cost, almost silent operation, undemanding - care is practically not needed. The rotor and impeller are immersed in a coolant, which simultaneously lubricates the rubbing parts. Care is reduced to the removal of air by simply unscrewing the screw.

Choosing a device - what to look for

The correct operation of the pump with full power output and proper circulation in the system is ensured by its selection according to the required parameters. Increased power is not at all necessary for high-quality heating. Such a unit will emit increased noise, the cost is greater, it wears out faster. In order to correctly select the optimal pump, a number of important system parameters are taken into account.

The calculation of the required power is made according to the formulas. The calculations are not very complicated, but the practical experience of users has led to a simplified approach that has justified itself. In this case, only two indicators are taken into account - the area of ​​\u200b\u200bthe room and the maximum height of the water rise. We study the marking of the pump, which may look different on the plate. For example, one of the accepted markings looks like this: 25-40/180. The first number indicates the diameter of the connecting pipe, the last number indicates the length of the set, which is almost always 180 mm, occasionally 130 mm.

These indicators are important for installation, and for power selection, we pay attention to the second number. In this case, 40 is the head, i.e. this device is capable of raising water by 4 m. Another marking method indicates H max (m) - the maximum height of the coolant rise in meters. The table below will help you choose a forced coolant supply device of the required power.

The table is indicative, the sellers of a specialized store will help you choose the device more precisely, but it will not be superfluous to know the necessary parameters and be able to read the plate.

Choose a place for the pump - on the supply or on the return

Theoretically, a forced coolant supply device can be installed anywhere close to the boiler. It is able to withstand a maximum temperature of 110°. But in reality, this method is rarely resorted to, primarily for practical reasons. Of course, the water temperature in the boiler will not reach 110°C, but it can be close to it. Constant elevated temperatures will not add additional years to the pump life.

But this applies, first of all, to systems of a private house with old boilers without a thermostat, especially solid fuel ones, where water can even boil. In modern boilers, the operating temperature is maintained by a thermostat, it rarely exceeds 60 °. Installing a circulation pump at the supply in this case will practically not shorten its service life. In addition, the water leaving the boiler is much cleaner than the one that enters through the return line. Even the filter that is installed with the pump cannot guarantee complete water purification.

The installation of a coarse filter together with a circulation pump is mandatory. The holes in it are very small, the smallest particles of rust and dirt can clog them.

Most of the recommendations still relate to the installation of the pump on the return line. This is justified by the fact that air is collected in the upper part of the boiler during operation, at the supply it is drawn out by a pump, a vacuum is created. There is a high probability that the boiler in this part will boil. On the return line, the water seems to be pressed into the boiler by the pump, no space with air is created. The boiler always remains completely filled.

The figure shows the installation diagram of the pump, where: 1 - heating device, 2 - automatic air valve, 3 - thermal valve, 4 - heating battery, 5 - balancing valve, 6 - expansion tank, 7 - ball valve, 8 - filter, 9 - forced circulation device, 10 - pressure gauge, 11 - safety valve.

Tapping the pump into the system is possible both at the supply in an open system, and at the return to a closed system with a membrane expansion tank, but it is also possible into an open system. The unit must be installed between the boiler and the expansion tank. It is better to replace the conventional expansion tank with a closed membrane one at the same time as installing the circulation pump, if the pump is to be installed on the return line. The water in it does not come into contact with the air, it remains clean, the pipes do not rust. The membrane tank is installed on the return before the circulation pump.

We mount the pumping unit - sequence and important points

Each installation is supplied with instructions, which we carefully study in order to correctly perform. We drain all the liquid from the system, cut off part of the pipe at the place where the heating pump is supposed to be installed. In many cases, it is necessary to clean the old system, which has accumulated dirt and rust. Through the drain tap, this is poorly done due to the small cross section of the hole, so we use the cut site. We connect a hose to one side, through which we supply water under pressure. On the other hand, water flows out, rinse until clean.

We install a bypass (bypass section) in the pump area. It is necessary in case of a pump breakdown or a power outage. Then the coolant will go through the main line, the valve in which we open manually. It is better to install an automatic one instead of a conventional ball valve, which reacts to a change in pressure in the system. We install two ball valves on the bypass on both sides of the pump to shut off the water for maintenance or remove it if necessary. On top of the bypass line we mount a valve for air release.

After installing the bypass, we mount the pump. The pump shaft is set horizontally, the more precisely, the better. If the position is not horizontal, only part of the rotor will be in the liquid, which will lead to a drop in power and even breakage. The terminal box is located at the top. The pump housing along the axis is securely fixed with connecting nodes. We treat the joints with a sealant, which will exclude the flow of liquid, air leakage and increase the performance of the device. When connecting the pump, we are guided by the insoles on the body, which indicate the direction of fluid flow.

A heating system designed exclusively for forced circulation will not be able to work when the electricity is turned off. For such cases, it is recommended to install additional power supplies.

By connecting electricity to the equipment, we exclude the possibility that moisture will get into the terminal box. If the unit is located on the supply line, it gets very hot, then we use heat-resistant wiring for connection. The cable must not touch the pipes, the pump housing. It is started from any side, except for the bottom, by rearranging the plugs. If the terminal box is located on the side, we start the cable from below. The device must be grounded.

After completing the installation work, we fill the system with coolant. We remove air from the pump by turning the central screw on the housing. When water appears, this will indicate the complete removal of air from the circulation pump. After that, we start the device. On the body of most pumps there is a knob for adjusting the power. We check the work in all modes. Some models are equipped with an electronic regulator.

The heater does not work - possible causes

Sometimes pumps break down or don't work well enough. The most common causes:

1. 1. Installed incorrectly. The horizontal shaft is not maintained or it rotates in the wrong direction.
2. 2. Incorrectly powered from the mains.
3. 3. Air has collected in the pump. It must be vented through the central screw each time before starting.
4. 4. Poorly purified water. The filter is clogged or incorrectly installed - marks indicating the direction of water movement are ignored.

Malfunctions are easier to prevent if you are careful during installation and start-up.