Circulation pump for heating: types, devices, selection criteria -

The forced movement of the coolant in the water heating system is provided by a circulation pump capable of pumping liquid at a temperature of 110...115 °C. In private houses and apartments with individual heat sources, low-noise appliances of the household series with a coupling connection, equipped with a “wet” rotor (the motor armature is washed and cooled by flowing water), are used.

If you decide to choose a heating pump yourself, consider 3 main criteria:

Technical characteristics - productivity, working pressure.
Connecting and overall dimensions.
Product price, brand popularity.

Let's consider point by point how to choose the right circulation pump for a radiator system, heated floors and the primary boiler circuit.

When is it necessary to install a circulation pump in a heating system?

The presence of a circulation pump in the heating system reduces the heating time of radiators to several minutes. It forcibly accelerates the coolant through the heating system, ensuring uniform circulation of hot liquid. The need to install it arises in cases where the natural circulation of the coolant cannot cope with heating the house.

Pumps are installed immediately when installing a heating system or during its modernization. Sometimes, errors in the design of heating systems are discovered only during operation.

The reason for poor heating of housing construction can be fouling of the internal walls of the system pipes with rust, scale or dirt.

This increases the hydraulic resistance in the heating system and deteriorates the circulation of the coolant in general in it or in certain areas. Installing a pump can help solve the problem of heating a home in such cases without completely replacing the heating system. The smooth operation of pumps depends on their correct installation.

FAQ

Will the pipes make noise when using the pump?

There can be noise in the pipes only if the device is chosen incorrectly or air has accumulated in the line. To remove air, do the following:

fill the entire system with water;
we remove air using valves on radiators - “air vents”;
we start the heating boiler and pump;
we wait for a while, after which we remove the air again;
check the pressure, fill the circuit with water;
we start the pump and adjust it (if it can be adjusted at all).

Is it possible to use a high pressure pump for water supply?

Definitely no! Even though they (pumps) look almost the same, in water supply pumping equipment is used solely to maintain the required pressure if for one reason or another it is not enough.

What are pumps made of?

Some parts (shaft, ball bearings) of modern pumps are made of ceramics. This not only ensures silent operation, but also significantly increases service life.

Are there pumps for hot water supply?

Yes, they exist. This is, for example, the GRUNDFOS Comfort UP circulation pump, thanks to which you don’t have to wait for hot water to start flowing from the tap. Of course, its use will increase the consumption of electricity and water itself.

How much energy do pumps consume?

In most cases, circulation pumps are extremely economical devices that consume as much energy as a regular light bulb. Recently, everything has been about assigning labels to products that indicate their “gluttony capacity,” as is the case with household appliances. A classification has been developed according to which A-class devices, for example, need no more than 6 W.

Note! Adjustable pumps are more economical!

How often do circulation pumps need to be replaced?

If the pump is of high quality, it will last about ten years. Although, as we have already said, a lot depends on the manufacturer itself. To ensure that your device lasts longer, follow all recommendations regarding operation: select the correct model and install it, avoid airing the line, use only specially purified water as a coolant.

What are the benefits of installing circulation pumps in heating systems?

Modern pumps allow you to regulate the intensity of coolant supply in the system automatically. Maintaining a constant temperature in it protects system parts from premature wear, and the uniform movement of coolant through pipes and radiators increases the service life of the thermal unit and expansion tank.

Other advantages of installing circulation pumps in the heating system include:

eliminating the possibility of air locks forming in the system;
increasing the efficiency of the thermal boiler and reducing fuel consumption for heating the house;
the possibility of installing heated towel rails and using small diameter pipes in the heating system.

Expert opinion

Grebnev Vadim Savelievich

Heating system installer

The main disadvantage of circulation pumps is their dependence on electricity. Interruptions in its supply can damage the devices.

How to choose

Often the UPS is offered together with the pump. But if it is missing, then the UPS will have to be purchased separately. Without it, your equipment in your home will be at risk.

But the main factors for choosing a pump are:

Pressure in the pump system;
Coolant flow;
Pump performance.

Pressure It can be selected correctly by calculating the hydraulic resistance. It is influenced by the size, length of the pipes, the number of turns, and narrowings in the system. The pressure must be able to overcome all resistance.
Consumption. It must be selected based on the load of the heating system. It is quite difficult to determine this on your own, so it is better to immediately turn to specialists.
Power. Based on the severity of our winter, 120 W of power is needed for every square meter of house area. If you live in a warm region, then 100 W is enough.

It is best to choose self-regulating pump models, since they are able to adapt themselves to operating conditions. They are the easiest to choose, and the price does not significantly exceed the cost of conventional models. Make sure that it is equipped with a reliable UPS that is responsible for load surges.

Types, features

Centrifugal-type devices operate on the principle of fluid intake by an impeller and ejection in a given direction. They work with equal efficiency for suction and discharge. All circulation pumps used in heating systems are divided into two main groups: wet and dry rotor. Each type of device has its own design features.

Glandless Rotor Pumps

Equipment of this type is considered the most suitable for domestic heating systems due to the low noise level they create during operation. In their structure they are similar to drainage units. Externally, pumps with a wet rotor can be distinguished from dry designs by the absence of fins on the motor housing and the impeller at its end.

Their impeller is mounted directly on the motor shaft. Seals are placed on it to prevent leakage. The housing has a sealed design. For its manufacture use: brass, cast iron, bronze or stainless steel. The pump rotor is most often made of ceramic material. A special feature of the design is its direct contact with water.

Centrifugal force is created inside the pump. The rotating impeller reduces the pressure inside the device body. This causes an influx of fluid. It increases the pressure. The resulting temperature difference creates conditions for pushing the carrier into the system.

Among the advantages of pumps of this type:

independent removal of air locks from the system;
less wear on pump parts;

self-cooling.

Dry rotor pumps

The device does not have direct contact with liquid. Pumps of this type have the highest efficiency. The structure is cooled using an air system. The main disadvantage of this type of equipment is the increased noise level during operation. Dry rotor circulation pumps are designed to work with large volumes of water. They are preferred when installed in the heating system of industrial facilities.

About the importance of the brand

There are a great many names of circulation pumps, but this does not prevent them all from having almost identical characteristics. And if there are significant differences, they relate mainly to reliability and service life.

Wilo circulation pump

The most popular brands today are Grundfos, Speroni, Wilo, ELSO-THERM and Wester. In addition to them, there are a lot of outright Chinese counterfeits and more (meaning “real” Chinese goods). The brands we list are considered by consumers to be the highest quality and most reliable. Circulation pumps from well-known manufacturers are almost silent. You can make sure that the device is working only by touching it, or by ear, but from a distance of a few centimeters. They are durable and can serve you for many years, but have a significant drawback - high cost (it is almost twice as much as less popular models).

Other brands are a middle option. They work well, their prices are reasonable, and breakdowns are rare.

The opinions of all buyers about pumps from China agree: sooner or later the devices begin to make noise, the rotor begins to “walk”. Their service life sometimes reaches several years, but in most cases does not exceed several months. Naturally, they are inexpensive.

The best circulation pumps for heating systems

Grundfos UPS 25-40 180

Country of origin: Serbia. The model is one of the most popular and in demand. Installation method: horizontal and vertical. The unit has protection against overheating. Operating the pump for pumping heavily contaminated liquids is strictly prohibited. The operating temperature limit is from 2°C to 110°C. The unit operation setting is mechanical.

Characteristics:

productivity – 2900 l/h;
power consumption – 45 W;

head – 3.8 m.

Advantages:

high performance;
affordable price;
reliability;
good pressure.

Flaws:

more expensive than similar domestically produced devices;
the model is often counterfeited.

"Whirlwind" TsN-25-4

Country of origin: Russia. The model is designed for pumping hot and cold liquids. Operating temperature range from -10°C to 110°C. The body of the product is made of cast iron. The optimal operating mode of the pump is selected using a special switch.

Characteristics:

productivity – 50 l/min.;
power consumption – 72 W;

head – 4 m.

Advantages:

low noise level;
ease of installation and operation;
long service life;
affordable price;
efficiency;
compactness.

Main disadvantage

discrepancy between the characteristics declared by the manufacturer and the actual ones.

Oasis CN 25/4

Country of origin: China. The model with a wet rotor is intended for installation in heating systems designed to heat rooms up to 100 sq.m. Installation method: horizontal. The body is made of cast iron, the rotor is ceramic. The model can be used to supply hot water and in underfloor heating systems.

Characteristics:

productivity – 170 l/min;
power consumption – 245 W;

head – 8 m.

Advantages:

efficiency;
compactness;
light weight;
long service life;
ease of installation and maintenance.

Flaws:

not identified.

Grundfos UPS 25-60 180

Country of origin: Denmark. Model with wet rotor. Designed for installation in horizontal and vertical positions. There are requirements for the purity of the liquid. Can be used for heating and hot water supply systems. The product has a bronze body. The pump has 3 operating speeds, with which the pressure in the system is regulated.

Characteristics:

productivity – 4.35 cubic meters/hour;
power consumption – 60 W;

head – 6 m.

Advantages:

several rotor speeds;
compactness;
reliability;
ease of installation and operation.

Flaws:

not identified.

Grundfos ALPHA2 25-60 180

Country of origin: Denmark. The low-noise pump model has a high quality design. Designed for installation in heating systems of low-rise buildings. The model has two settings: manual and automatic. The device installation method is vertical.

Characteristics:

productivity – 3 cubic meters/hour;
power consumption – 45 W;

head – 6 m.

Advantages:

low noise level during operation;
ease of installation and operation;
reliability;
long service life.

Main disadvantage:

high price.

Valtec VRS 25/4 130

Country of origin: Russia. Model with wet rotor and three-stage speed switch. The body of the product is made of cast iron. Installation method: vertical and horizontal. The maximum operating temperature limit is 110°C. The rotor is cooled by the pumped liquid.

Characteristics:

productivity – 3000 l/hour;
power consumption – 72 W;

head – 4.2 m.

Advantages:

reliability of the design;
affordable price;
ease of installation and operation.

Main disadvantage:

short standard power cord.

JEMIX WRF-50/12

Country of origin: Russia. Model with wet rotor. The pump has an aluminum single-speed motor. The product is intended for installation in heating systems of small cottages. The method of connection to the pipeline is flange. The pump is installed directly into the pipeline.

Characteristics:

productivity – 9600 l/hour;
power consumption – 550 W;

head – 12 m.

Advantages:

high pressure;
reliability;
high efficiency.

Flaws:

the need to weld counter flanges to the pipeline;
high price.

WWQ CN 25/60-180

Country of origin: Russia. Three-speed model with a wet ceramic rotor. The pump is designed for installation in the heating system of low-rise buildings.

Characteristics:

productivity – 58 l./min.;
power consumption – 90 W;

head – 6 m.

Advantages:

overheat protection;
ease of maintenance and operation.

Main disadvantage:

short network cable.

Wilo

High quality, as always, was considered the trademark of any German product. The Wilo Star RS 25/4 circulation pump is no exception.

Both consumers and experts note such advantages of the device as:

ease of installation;
reliability;
fast connection;
three power levels.

Another advantage of the installation is the absence of the need for systematic maintenance.

What to consider when choosing

The determining factor in choosing a circulation pump for a heating system is its performance. To pressurize large-diameter pipes, it is necessary to install units with high power. When installing pumps in a separate room, the temperature conditions of the equipment must be taken into account.

Other factors influencing the choice of circulation pumps for heating include:

principle of operation;
method of connection to the system;

number of circuits.

When purchasing a pump, you should pay attention to the manufacturers' recommendations on room heating standards. These values differ depending on the country in which the unit is installed.

Expert opinion

Grebnev Vadim Savelievich

Heating system installer

The functionality of the devices is important. It is preferable to install pumps with automatic adjustment of operating modes in heating systems.