The heating circulation pump is heating up: the water pump in the heating system, why it is heating up, what to do

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.

Circulation pump electrical connection diagram

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.

Where to connect the power cable

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.

How to connect a circulator to electricity through a stabilizer

How does the circulation mechanism work?

When the pump is turned on, water in the heating system (in a closed circuit) is drawn into the inlet under the influence of the rotation of a wheel with blades

When the pump is turned on, the water in the heating system (in a closed circuit) is drawn into the inlet under the influence of the rotation of the wheel with blades. The water that gets into the chamber, due to the action of centrifugal force, is pressed against the walls of the working chamber and pushed out (into the outlet). Following this, the pressure in the chamber drops, which promotes a new injection of water into the pump reservoir.

Thus, during a continuous cycle of pump operation, the heating system can be in a state of a constant set temperature, which significantly reduces the cost of fuel or electrical energy consumption for heating water.

Operating rules

To prevent breakdowns, follow the operating rules:

It is prohibited to operate the house heating pump if there is no water in the system;
do not use the unit at zero supply;
During operation, feed limits are observed;
to prevent oxidation during downtime, the unit must be turned on for fifteen minutes;
the temperature of the working fluid does not exceed sixty-five degrees Celsius;
no leaks at pipe connections;
no heating of the unit;
Do-it-yourself pump installation involves horizontal placement of the shaft.

If the rules are followed, the unit can last ten years.

Calculating pressure in two ways

design. At this stage, a decision is made about which rooms will be heated and which will not, diagrams are drawn and the volume of the system in liters is calculated;
boiler selection. Based on the volume of the system and the area of the heated premises, a heater is selected. For 15 liters of coolant, one kilowatt of heater power is required;
determining the required volume of the expansion tank.

Now let's look at several different methods for calculating the pressure in the expansion tank of a sealed heating system.

Option #1.

For this we need the following quantities:

system volume (OS);
tank volume (VT);
the maximum permissible value of the pressure gauge scale for a given system (DM);
water expansion – 5%.

By the time you have to make calculations, you already know how many liters the system holds. The required volume of the tank is calculated by dividing the capacity of the circuit in liters by ten. Although this is an approximate calculation, it is very working.

The volume of the tank in a closed system may be more than necessary, but it cannot be less. An error will lead to replacement or installation of an additional one.

Air vent

Option #2.

It's good that we live in a world of fierce competition. To ensure that the client is satisfied with the purchase and does not have any problems with operation, boiler manufacturers indicate the required pressure of the heating expansion tank in the product data sheet. If for some reason this cannot be found out, then you can calculate this value, knowing what the pressure gauge readings should be in the operating mode of the system.

The latter can be found with one hundred percent probability in the technical documentation or on the boiler. Then 0.2-0.3 atmospheres should be subtracted from the working pressure. What is it for? If the pressure in the tank is greater than the working pressure in the system, the coolant will not be squeezed into the tank. He simply cannot do this, as an even greater force acts on him from the side of the tank. And if there is not enough air in the tank, then there will be difficulties with returning the coolant to the system.

Why does the circulation pump heat up: the main reasons and methods for eliminating them

There are several possible situations that indicate problems with such a device.

Incorrect installation

If the location of the rotor is incorrectly determined and its axis is displaced from the horizontal, there is a possibility of an airing effect. As a rule, it will be possible to find out about such an erroneous installation of the device immediately after the start of operation of the heating system.

To solve this problem, you will need to correct the rotor position.

Photo 1. Installation diagram of the circulation pump in the heating system. To install it you will need many components.

The device heats up due to a clogged system

The process of circulating coolant through pipes is fraught with the formation of rust and the accumulation of deposits. As a result, the pipes narrow, and the pumping equipment has to increase its own load to push the liquid. This is how it overheats. Cleaning the heating structure will resolve this situation.

Reference. A solution of caustic soda helps, filling the heating system for 1 hour.

Foreign body

Corrosive particles from old pipes or batteries break off over time and enter the circulator's motor, blocking its operation or causing the windings to burn out.

Unscheduled maintenance of the heating system will help, allowing you to get rid of foreign elements, and repair (or replacement) of the pump.

Lack of bearing lubrication

When it is deficient, bearings wear out at an accelerated rate. Due to their unsuitability for further operation of the device, its main element, the engine, jams.

Photo 2. Diagram of a circulation pump with a wet rotor. The arrows indicate the location of all parts, including bearings.

The heating system device will have to be dismantled and taken for professional diagnostics.

Low voltage in the network

An indicator of this parameter below 220V provokes rapid airing of the pumping equipment and its failure. Determining the voltage in the network by using a voltmeter will help prevent the problem.

Insufficient pressure

Overheating causes incorrect phase connection when a three-phase wheel with blades is included in the heating circuit. In this case, the direction of its rotation will be disrupted. Insufficient pressure also occurs when the viscosity of the circulating fluid is increased. In this situation, the impeller encounters quite a lot of resistance.

To solve the problem, at the first sign of its manifestation, it is necessary to check the cross-section of the incoming pipe, set the required pump adjustment data and eliminate possible deposits on the inlet pipe filter.

Stopping after start

This problem occurs when the phase wires in the terminal box are incorrectly connected. And the fuse of the device is equipped with a loose contact.

To fix the problem, you need to remove it and thoroughly clean the clamps.

Installation diagram

In practice, two schemes for installing a circulation pump are used in a single-pipe and two-pipe heating system. Before carrying out installation work, you must carefully study the attached instructions. At the preparatory stage of work, water is drained from the system and the pipes are cleaned of contamination by additional pumping of liquid. The pump is installed according to the attached diagram, then coolant is poured into the circuit and the unit is turned on.

As we have already said, it is best to install the pump on the return side using a tap or, as it is also called, a bypass. Such a device is necessary to shut off the water and replace the pump in case of breakdown. The diameter of the outlet pipe should be smaller than that of the central pipeline.

Installation diagram of an additional pump in the heating system

At each edge of the bypass, before entering and after exiting the pump, taps are installed for emergency shut-off of the coolant. Another valve is installed on the central line to direct the flow of liquid through the pump. Before entering the pumping equipment, a special filter is attached that will accumulate harmful particles in the water.

Actions for prevention

In operating condition, monitor the engine heating level. If it seems too high to you, then it is better to remove the pump and contact the point of sale with a request to replace the unit. The same can be done in case of pressure mismatch

Also, to protect pumping equipment from sudden failure, it is recommended to carry out preventive maintenance of the unit, which will include the following actions:

Regular external inspection of the pump housing and careful listening during operation. This way you can check the functionality of the pump and the tightness of the housing.
Make sure that all external pump fasteners are properly lubricated. This will make it easier to disassemble the pump if repairs are necessary.
It is also worth following some rules when installing a pumping unit for the first time. This will help avoid repair work in the future:
So, when you first connect the pump to the heating network, you should turn on the unit only if there is water in the system. Moreover, its actual volume must correspond to that indicated in the technical passport.
It is also worth checking the coolant pressure in the closed circuit here. It must also correspond to what is stated in the technical specifications of the unit.
In operating condition, monitor the engine heating level. If it seems too high to you, then it is better to remove the pump and contact the point of sale with a request to replace the unit. The same can be done in case of pressure mismatch.
Also, make sure that there is a ground connection between the pump and the terminals when connecting the pump. Here in the terminal box, check that there is no moisture and that all wiring is securely fixed.
A working pump should not produce even minimal leaks. The connection points between the inlet and outlet pipes of the heating system and the pump housing deserve special attention.

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.

Installation diagram of a circulation pump in a system with natural circulation

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 thing: with a vertical arrangement, the power (pressure created) drops by about 30%. This must be taken into account when choosing a model.

Best answers

Marat Musin:

LOOK AT THE PASSPORT WHAT LIQUID SHOULD BE FILLED

******:

It looks like it runs dry or there is no water flow through it.

Vladimir Petrov:

Check the system; it looks like your water is simply flowing poorly into the new branch or not at all. And you cleaned the filter, maybe that's the problem. Or on a new branch of a pipe of small diameter. And also check that you have installed it correctly, there is an arrow in the direction of the water

Viktorij Lashhehova:

❝Actually, what could be the problem? ❞If there were financial disagreements when paying with the contractor, then you need to resolve them and then everything will work correctly for you.

Stubborn Like Dac:

It appears that the pump rotor is not turning. At the end of the pump there is a plug with a slot for a screwdriver. Unscrew this plug and tap on the rotor axis with a metal object (for example, the same screwdriver) ... I had a similar situation last year and after several light blows with a screwdriver, the pump started working and is still working.

The device is so hot that you don't even need a boiler! Why does the pump in the home heating system get hot?

Improper operation of the circulation pump leads to various problems, including overheating.

Due to overheating, pumping equipment may fail, which will lead to the stoppage of the entire heating system. This is especially dangerous in winter.

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Odnoklassniki

The purpose of installing such a device is to pump fluids in the heating system and create pressure. These processes help heat the heating device, but not critically.

The temperature of the circulation unit and pipes should be approximately the same. If the deviation is large, then this is already overheating of the device.

Incorrect installation

To solve this problem, you will need to correct the rotor position.

Photo 1. Installation diagram of the circulation pump in the heating system. To install it you will need many components.

The device heats up due to a clogged system

Reference. A solution of caustic soda helps, filling the heating system for 1 hour.

What to do if pumping equipment gets hot

When such a situation arises, the first thing you should pay attention to is the openness of the shut-off valves. Next, check the correct installation of the pump, its rotation and check valve

Air masses need to be vented from the heating device.

Attention! The rotation of the circulation pump must be in the same direction as the arrow marked on the housing. Compare the temperature of the unit itself and the check valve

The indicator should not differ much

Compare the temperature of the unit itself and the check valve. The indicator should not differ much.

The problem may also be in the load consumed by the device. To do this, each of its phases is checked.

Alternatively, the pump is disassembled and washed to eliminate the possibility of clogging.

It is necessary to resort to such a measure if performing simple actions does not help solve the problem and you need professional advice on how to get out of the current situation.

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Which one to choose?

When choosing, you need to pay attention to the following features:

Rated current. Now the market offers 220 Volts, which is convenient. But you can get into a promotion and buy a good 380 device cheaply, and then wonder what to do with it.
Maximum operating fluid temperature. The standard is 110 degrees, which is enough for any home. But it’s worth paying attention to the indicator so as not to get into trouble.
Power. This is the electricity bill. Usually the device is taken with a reserve, but for a small apartment a powerful device is not needed at all; it’s extra money when purchasing and using it.
Performance. Probably the main characteristic. There is a certain set of formulas that allows you to calculate the indicator necessary for your conditions. But you don’t have to go deep into the mathematical jungle and use online calculators, of which there are many on the Internet.
Thread diameter and installation length. If the heating system is already installed and you just need to cut into it, then these indicators are vitally important.
Protection class. Today it is mostly IP44. It is enough that particles larger than 1 millimeter in diameter do not get inside, and drops of water from any angle do not cause a short circuit. You can buy a higher class, but a lower one is not recommended.
Switching operating modes. A convenient option that will allow you to regulate the performance and, accordingly, the current consumption of the coolant.
Water column. If there are 2 floors or more, a basement, then you should pay attention to the parameter. In other cases, any pump can drive water from floor to ceiling.

Installation procedure for the circulation pump

Before connecting the unit, you need to choose the right location for placement.
It is important to remember that the device requires periodic maintenance, and therefore there must be enough free space near it. The most optimal area for placing the device is in front of the boiler unit. This scheme will prevent the formation of air jams. Additional advantages of this option are that the unit will operate with a low-temperature coolant, which will significantly increase its service life. An equally significant point in installing a centrifugal unit is the location of the working shaft. It must be remembered that the shaft must be placed exactly in a horizontal position. Otherwise, it will not be able to be completely immersed in a liquid medium, which will cause a significant loss of productivity and will contribute to the rapid decommissioning of its working units.

With dry rotor

A similar pump for heating a house got its name due to its design features. The features of the proposal are the following:

Only the impeller is immersed in the coolant. It can be made using various materials. Most attention is paid to those that can withstand high temperatures.
The rotor is located in a sealed housing. Several O-rings are used to protect the device.
The efficiency indicator is 80%. Such productivity can be called very high.
The service life is approximately 3 years.
The structure requires regular maintenance. This is due to the fact that solids from the coolant can get onto the O-rings.
There is a lot of noise during operation.

How circulation pumps are designed and work

The operating principle of circulation pumps is not much different from the design of drainage models. The device body is made of durable materials that are resistant to corrosion. Typically this is stainless steel, aluminum, brass, cast iron. When started, the engine begins to rotate a rotor equipped with an impeller. As a result, the pressure at the inlet pipe decreases and water is sucked into the hydraulic chamber. The rotation of the impeller creates centrifugal force. Water is pressed against the walls of the chamber and forcefully thrown into the pipeline through the outlet. This ensures forced circulation of the coolant in a closed heating circuit.

Design differences between different types of devices

There are two main types of pumps - with “wet” and “dry” rotors. The “wet” rotor is separated from the water by special sealing rings, between which there is a thin film of water. When worn, the rings wear out and are pressed closer to each other, which guarantees the tightness of the structure for several years. Cooling and lubrication are provided by the working fluid. Pumping equipment of this type is installed in systems with small coolant volumes, because It is difficult to ensure tight connections in large-diameter structures

When installing devices, it is important to ensure that the shaft is positioned strictly horizontally, otherwise the device may malfunction

The main advantage of “dry” models is their high efficiency. It is 80%, which distinguishes it favorably from the 50% efficiency of “wet” type devices. The rotors of “dry” heating circulation pumps do not come into contact with the liquid. Depending on the location of the engine, structures are divided into horizontal (cantilever), vertical and block. All “dry” models are noisy during operation and are sensitive to the quality of the coolant and air purity. It is advisable to install them in separate rooms of boiler rooms, controlling the purity of the water in the system and the air in the room.

Main varieties

There are different types of circulation pumps. Design features largely determine how a structure performs. There are two main types of equipment under consideration:

With dry rotor.
With wet rotor.

Dry rotor circulation pump

Circular pumps for heating systems are produced by various companies. The quality of the materials used determines how long the structure can last. In addition, there is a recirculation pump for heating.

Classification can also be carried out according to the following indicators:

The type of material used in the manufacture of the case.
Size and power.
Installation type.

Glandless circulation pump

Most models have similar performance characteristics, taking into account which allows you to choose a more suitable version. Let's take a closer look at the design features of the dry and wet rotor versions.

How circulation pumps are designed and work

Design differences between different types of devices

When installing devices, it is important to ensure that the shaft is positioned strictly horizontally, otherwise the device may malfunction

Why does the circulation pump heat up - the main reasons

Ideally, the pump temperature should be the same as the coolant pipes. If it is higher, it means that either errors were made in the installation, or there are problems with operation. Typically, the circulation pump of the heating system gets hot for the following reasons:

– Incorrect installation. The easiest way to determine the presence of installation errors is: the device begins to overheat at the initial stage of operation of the heating system.

– Clogged system. Over time, various deposits and rust accumulate in the pipes. This leads to a narrowing of the water passage diameter. The pump has to work at increased load to push the coolant into the narrowed pipes, and the electric motor overheats. Preventive measures will help “cure” it - unscheduled maintenance of the heating system.

-Foreign body. If communications are slagged, pieces of rust or limescale may come off the internal surfaces of pipes and radiators. When they get into the pump, they jam the electric motor. The result is usually predictable: if you do not disassemble and clean the device in time, the motor coils will fail.

– Lack of bearing lubrication. If it is not enough, the bearings wear out much faster, which shortens the service life of the entire device as a whole. The engine jams. It is advisable to dismantle the pump and take it to a workshop.

–Low voltage in the network. If the voltage is below standard 220 V, the engine overheats and quickly fails. At the first signs of overheating, it makes sense to determine the voltage in the network using a voltmeter. Perhaps the problem is not in the pump itself.

If the circulation pump gets hot, the reasons can be very different. Do not rush to dismantle the device. First, measure the voltage in the network. If it is normal, flush the system with caustic soda, filling it for at least an hour, and then draining the solution. If this does not help, contact a specialist, otherwise the device will burn out and you will have to buy a new one, because rewinding the motor windings can be more expensive.

Forced circulation of thermal energy carrier

To ensure complete and rapid heating of all rooms in the house, forced movement of the coolant is used. Pumps are installed in different buildings, provided that this was planned in the heating system design.

Thanks to the operation of pumping equipment, it is possible to provide comfort in the building that does not depend on weather conditions and climate in the region. But, like any type of equipment, the pump can break. What to do and why does the heating circulation pump get hot? Can I eliminate the causes of the problem myself?

Design features of the circulation pump

The pump housing is made of materials that are durable and resistant to corrosion, usually:

After the engine is started, the rotor in the pump, which is equipped with an impeller, begins to rotate. After this, the pressure at the inlet pipe decreases, as a result of which the liquid is sucked into the hydraulic chamber. Due to the rotation of the impeller, centrifugal force is generated.

The liquid medium is pressed against the walls of the chamber and thrown out through the outlet into the pipeline. This ensures forced circulation of the coolant in a closed heating circuit.

Should it be warmed up?

The main reason for installing this type of pump is the forced acceleration or deceleration of fluid flow through pipelines under pressure. Due to the conversion of electrical energy into kinetic energy, and due to the friction of the pump components among themselves during operation, its heating should be observed. However, temperatures increase slightly. The pump accelerates hot water, which also contributes to heating. Therefore, the heat generated by the pipe should be approximately the same.

It is much worse if the pump is much hotter than the pipeline. This indicates a malfunction.

Why does it smoke?

If the stove in the bathhouse smokes during initial use, the problem may directly be due to improper installation of the structure. We strongly recommend that you contact a specialist for help, since it will be quite difficult to find and fix the problem yourself.

In addition, there are other reasons why the stove in the bathhouse smokes. These include:

First of all, strong winds can interfere with the exit of smoke from the chimney. In most cases, this is due to the fact that the pipe is located slightly below the ridge. The problem can be solved by making the pipe longer, or by installing a protective cap;
Damage to the roof may also be the answer to the question - why does an iron stove smoke in a bathhouse? This is explained by the fact that if there is an attic flue, moisture enters it and seeps through damaged roof areas. This problem can be eliminated only by repairing these areas;
An iron stove in a bathhouse smokes most often due to an excessively dirty chimney or foreign objects in it. Detecting this problem is as easy as shelling pears, since a clear sign is poor draft in the sauna stove. For example, very often birds build nests in chimney pipes, and debris and branches from nearby trees can get into an unprotected pipe. This problem can be solved quite simply; you just need to clean the chimney of soot, soot and foreign objects. As a tool, it is best to use a special flexible brush with nylon bristles;
Among other things, smoke can be caused by too large a vent. This is explained by a large amount of cold air entering the hole, which subsequently heats up and pushes the smoke out.

The stove in the bathhouse is smoking - what to do? This is a rather serious problem that is easier and cheaper to prevent than to solve.

Attention! It is very important to properly design the stove and chimney to avoid smoke problems in the future.

chimney pipe

Problems arise due to the fact that strong air currents form above the roof, preventing the smoke from fully escaping from the chimney.

That is why the following factors should be taken into account at the design stage:

If the pipe is located at a distance of 1.5 meters from the ridge, then its height should exceed the level of the top of the roof by 50 cm;
If the pipe is located at a distance of 1.5 to 3 meters, then it is permissible to install a pipe whose height is equal to the level of the ridge;
If the chimney is located at a fairly significant distance, which exceeds 3 meters, then the pipe should be no lower than an angle of ten degrees from the ridge.

What to do if pumping equipment gets hot

If a problem occurs, pay attention to the openness of the shutoff valve system. Then you need to check whether the pump was installed correctly. The choice of installation location also matters.

Next, you need to check the return valve and rotation mechanism. Additionally, carry out preventive maintenance of the system and release excess gas from the pipes. You can compare the heating of the pump and the return valve. If it differs too much, you need to contact a specialist.

The malfunction occurs due to power supply. You need to check each of the phases with a voltmeter probe. Finally, you can flush the pump.

The pump for forced supply of liquid to the heating system becomes very hot during operation. This is a common problem in private homes and is associated with many factors. To prevent damage to equipment, it is advisable to carry out preventive maintenance and repairs in a timely manner. In this case, the heating of the room will not be interrupted at the wrong time.

Maintenance of circulation pumps

Pump malfunctions and ways to eliminate them

The design of a circulation pump with a “wet” type rotor is based on a modular principle. Modules can be configured in different configurations. It all depends on the power and size of the pump.

Any repair work can only be carried out if the power is completely turned off and the area has been drained.

Malfunctions of the heating circulation pump:

The pump turns on, sounds are heard, but the shaft does not rotate. Why is the heating pump noisy and why do other “symptoms” appear? The reason may be oxidation of the shaft after a long period of inactivity of the device. If the pump is blocked, the device must not be left on. It is necessary to drain the water and all the screws that connect the pump housing with the electric motor must be unscrewed. Next, we remove the engine itself, and its impeller is turned manually. If the pump is of low power, the shaft can be unlocked by turning it with a screwdriver. For this purpose, there is a special notch at the end of the shaft.
A foreign object has blocked the wheel. How to disassemble a heating circulation pump? We dismantle the pump motor using the above method. To prevent blocking from happening again, a mesh type filter must be installed in front of the pump.

There are problems with the power supply. It is necessary to check the voltage in accordance with that indicated in the technical data sheet of the device. You should also check if all phases are present and if everything is connected correctly in the terminal box.
The circulation pump does not make sounds (the heating circulation pump does not hum) and does not turn on. There is also no supply voltage. The fuse may be damaged. In this case, the fuse will need to be replaced. If nothing has changed after replacement, then the reason may be in the motor winding. Most likely it burned out.
The pump turns on, but after a while it turns off. The cause may be deposits that have formed between the rotor and the stator jacket. It will be necessary to dismantle the electric motor and clean the stator jacket from scale.
When the pump is turned on, a sharp noise occurs. Why is the heating pump humming and how to de-air the heating circulation pump? It is necessary to release the air and install an automatic air vent at the top point of the pump piping unit.

The pump vibrates. The cause may be bearing wear. Typically this problem is accompanied by a characteristic noise. To eliminate the problem, the bearing will need to be replaced.
The water pressure and its supply are lower than those indicated in the circulation pump passport. This malfunction is typical for three-phase type pumps if they were connected incorrectly.
After the pump has been started, the external protection of the electric motor is activated. Most likely, the problems occur in the electrical part of the engine.
It is necessary to check if there are phases in the terminal box. You also need to check if the fuse contacts are dirty. You can also check what the phase resistance to grounding is.

The circular pump creates conditions for the circulation of coolant throughout the entire heating system. Using this device allows you to improve heating performance and increase system performance. When installing pumping equipment, you can choose pipes with a smaller diameter, which allows you to save money.

Recommendations for selection

Circulation pumps for heating private houses are produced by quite a large number of different companies. The extensive selection makes it difficult to select the most suitable model. When considering how to choose a circulation pump for heating, you should pay attention to the following points:

The first thing to pay attention to is the performance of the installation. It is selected depending on the power of the heating boiler. An example is the case when the boiler power is 35 kW, for which a model with a capacity of 35 l/min should be selected.
Often a circulation pump is installed in order to provide a certain pressure in the system. Measurements indicate that a head of about 0.6 meters is required per 10 meters of pipeline. The calculation is carried out as follows: with a pipeline length of 80 meters, 8 should be multiplied by 0.6. The resulting figure will be the minimum for the system.
When choosing a device for heating a private home, it is recommended to give preference to models that can regulate the flow rate. Due to this function, it is possible to adjust the flow rate depending on what pair of years it is. High speed allows you to significantly increase the heat transfer of heat exchangers.
The power of the device is selected depending on the diameter of the pipes. For versions with a smaller diameter, circulation pumps with higher electrical power are installed.
The presence of protection can significantly extend the service life of the structure. For example, let's call dry-running protection. Almost all models cannot work in the absence of working fluid, as it becomes cooling.
Attention is also paid to what material is used in the manufacture of the case. The best option is to use cast iron; cheap models are made using cheap plastic. It is worth considering that cast iron is highly resistant to moisture, as well as good strength, but an impact can lead to a defect. Plastic does not withstand mechanical stress, but is characterized by light weight and resistance to environmental influences.
Case dimensions and shape. As productivity increases, the size also increases. Many models are represented by a combination of inlet and outlet pipes, as well as the main active part, made in the form of a cylinder. The control unit can be located on the side in the form of a small remote control with buttons. On the front side, as a rule, the manufacturer's information is placed.
Do not forget that manufacturers provide a guarantee. Some models have a warranty of about a year, others longer.

Typical circulation pump malfunctions

Compliance with all operating rules of the device does not guarantee uninterrupted operation of the unit. Breakdowns may occur that do not depend on human actions: the filter is clogged, voltage surges, etc.

If the engine does not turn on, but the pump does not make humming or other strange sounds, it is worth checking the fuse. It reacts sharply to surges in the electrical network and if the engine is threatened, it melts, thereby breaking the electrical circuit. In this case, the fuse will have to be replaced, after which the device will return to normal operation.

If the failure was not in the fuse, you should check the power cord, the circuit breaker in the distribution box and the electrical wiring. There may be a section of wire or switch that needs replacing.

After checking the wiring, you should move on to the electric motor winding. Its serviceability is checked by measuring the resistance. The multimeter should read 10-15 ohms. Some units are equipped with a starting winding, the resistance of which is 35-40 Ohms.

If the multimeter displays “infinity,” it means the winding has failed. And when the readings are closer to zero, an interturn short circuit has occurred. In this case, turning on the device is accompanied by the operation of fuses in the panel.

Modern devices have a low noise level, so often the owner of such a unit cannot understand whether it works or not? To diagnose the device, use a circulation pump shaft rotation tester indicator, which will show whether the device is working without an electrical outlet. To do this, you need to bring your indicator to the motor shaft and the scale will show whether the shaft is rotating or not working at all.

When the circulation pump hums, but the shaft with the impeller does not rotate, you should immediately turn off the unit, because the motor winding may burn out. There are several reasons for this malfunction:

The shaft does not work due to downtime in the summer. For the same reason, the impeller sticks to the housing. In this case, you need to disassemble the device and manually rotate the shaft. Manufacturers took this point into account, so the shaft has a notch for a screwdriver.
The impeller does not rotate due to a foreign object in the chamber. After removing it, system operation will resume.

If the device makes unusual noise during operation, this may be air accumulated in the system. To remove it, it is recommended to install an automatic air vent on the heating circuit. But if it is not there, then the air is bled off manually

Why does the circulation unit heat up?

The temperature of the device must match the temperature of the coolant pipes. If it rises higher, it means that errors were made during installation, or improper operation was taking place. The circulation unit may overheat for the following reasons:

initially incorrect installation. It is not difficult to determine the problem: the pump heats up at the initial stage immediately after installation.
blockage in the system. During long-term operation, deposits and rust accumulate in the pipes, which leads to a decrease in water passage. The device is overloaded to ensure normal coolant circulation. In this case, the engine overheats, but unscheduled maintenance can cope with the breakdown.
foreign body. When communications are slagged, pieces of rust or plaque break off from pipes and radiators, which, when they get into the device, jam the electric motor. If the device is not disassembled and cleaned in time, the electric motor coils may fail and the device will simply stop turning on.
Lack of lubrication for bearings. If there is insufficient amount of lubricant, the bearings are poorly lubricated and quickly wear out, which leads to a reduction in the service life of the unit as a whole. If the engine jams as a result, the pump is dismantled and handed over to a service center.
low voltage in the network. At voltages below 220 V, the electric motor overheats and quickly fails. In the first minutes of overheating, it is worth checking the voltage in the network with a voltmeter, because the problem may not be in the pump.

The device works, but does not pump coolant

One of the problems that happens with heating units is the operation of the pump without pumping water. There are four reasons for this condition:

air ingress or water leakage, which can be eliminated by repairing holes and cracks in the pipes;
incorrect adjustment of the heating system. The malfunction can be solved by checking the correct position of the taps (primarily before the pump);
no water. To repair such a malfunction is to supply water to the device.
Valve blocked or stuck. To resolve, repair or replace the valve.

Date: September 25, 2022