In a forced circulation heating system, the heart is the circulation pump. The presence of heating and its quality depend on its stable operation. The same applies to closed hot water supply systems with a constant flow of water in the pipes between the boiler and the storage tank. During operation, the question inevitably arises of how to service and repair the circulation pump so that it continues to operate stably and without failure.
For normal operation of the pump, the following measures must be taken:
The more accurately the operating rules are followed and the more regularly the pump is serviced, the less often you will have to think about repairing or replacing it.
A number of simple requirements apply to any circulation pump:
In operating mode, the pump must have a uniform sound of the operating drive and a constant output pressure value, which is monitored by an installed pressure gauge. If handled well, even the simplest circulation pump can operate for up to 5 years until its main elements wear out.
Almost all circulation pumps are centrifugal type. They have an impeller mounted on the motor shaft and placed in a special “shell” chamber. The entrance to the shell is located in the center, while the exit is the outer edge of the shell with a channel extending around the circumference in the direction of movement of the impeller. The engine spins the impeller, and water, under the influence of centripetal force, rushes from the center to the edges of the sink from inlet to outlet.
Pump structural elements:
The most susceptible to wear is the moving part of the pump - the motor shaft and impeller, as well as the bearings on which they are mounted.
Long service life and trouble-free operation are possible only if proper operating conditions and regular maintenance of the pump are observed. Maintenance means periodic inspection and cleaning of the pump. Inspection for abnormalities in operation should be carried out at least once a quarter, that is, twice during the heating season. It is advisable to perform cleaning every two to three years, depending on the quality of the water and the conditions in which the pump operates.
During the entire period of operation, it is advisable to periodically check the operation of the pump:
Approximately every two to three years, it is advisable to clean the pump, including all its elements. This only applies to models that can be disassembled. There are pumps with a pressed or solid, welded casing that does not require repair or disassembly. Such units fail and are then replaced with a new assembly. It is advisable to entrust this work to a service center. However, if you have the skills and tools, you can do everything yourself
Required:
Before disassembling the pump, drain the water from the system or drain a separate area in which the pump is involved, dismantle it and then begin disassembly.
Procedure:
The analysis is now complete. Now you should clean the surface of the rotor, impeller and the inner surface of the shell from plaque and scale, if any, without damaging the surface of the parts. It is not permissible to use a coarse abrasive. It is better to use a brush with hard polymer bristles. Cleaning products containing a weak solution of hydrochloric acid can help. As a last resort, the finest sandpaper is used - “zero”.
For glandless pumps, it is important to check the cleanliness of the channel inside the shaft and the drainage holes located in the protective jacket separating the area of the pump part and the motor. The fluid enters the rotor precisely through these holes and then returns through the internal channel; if they are clogged, engine cooling suffers.
For pumps with dry rotor Waterproofing the support bearing is important. If a leak is detected from the pump block to the stator block, then all gaskets and seals inside the device should be completely replaced.
The condition of the bearings on which the shaft rests is checked. If they are already quite broken, they will need to be replaced, which is extremely difficult to do at home; you will have to contact a service center.
All seals and gaskets inside the pump should be checked for wear and replaced with new ones if necessary. Once all elements have been cleaned and checked, reassembly is carried out in reverse order.
Circulation pump needs cleaning Based on how the pump operates, sound, vibration or changes in pressure, outlet pressure, it is necessary to accurately determine the malfunction and eliminate the cause.
| Symptom of malfunction | Probable Cause | Repair |
| The pump makes sounds after switching on, but the shaft does not rotate | Shaft oxidation due to prolonged inactivity | Unscrew the protective cap from the end of the shaft on the motor housing and manually turn the motor shaft using a slotted screwdriver. |
| Blocking by a foreign object | Disassemble the pump block with the impeller and clean it, check the condition of the coarse filter installed in front of the pump | |
| Power problems | Check the voltage rating in the network and correct the problem if necessary. | |
| After applying voltage, the pump does not start and does not make any sounds. | No actual voltage on power line | Check the power line and the condition of the circuit breakers |
| The fuse in the control unit has tripped | Replace fuse | |
| The pump turns off after a short period of operation | Limescale deposits in the stator cup | Clean the stator cup and motor rotor |
| Strong extraneous noise when the pump is running | Dry running, presence of air in pipes | Release the air. Drain the pump shell and fill with water. |
| Cavitation | Increase the pressure in the supply line. | |
| Pump vibration | Support bearing wear | Replacing bearings |
| Reduction of pressure and flow in comparison with the passport data | Abnormality in the power supply to the pump, phase change, resulting in a decrease in pump power or a change in the direction of rotation of the impeller | For three-phase motors, the quality of all phases is checked. For single-phase power supply, check the capacitor and replace if necessary |
| High hydraulic resistance of the circulation circuit | Check the filters, increase the cross-section of the pipes, check the condition of the shut-off valves. | |
| Triggering of external protection on the pump power line | Problems with the electrical part of the pump | Check the condition of the terminals for short circuits, check the capacitor and the control unit. Check the stator windings. Their resistance should not be lower than the rated value. |
It is best to take a broken circulation pump to a specialized service center, especially if it is still under warranty. Most of the models currently on the market, unfortunately, are non-separable or partially disassembled, so if problems arise with its internal spare parts, entire units or the pump assembly must be replaced. If the warranty period has already expired, and the design of the pump allows you to disassemble it and get to all the main components, then, if you have the appropriate skills, you can carry out the repair yourself.
Having determined the cause of the malfunction from the table above, it is enough to disassemble the pump, as indicated in the paragraph on prevention and maintenance, and replace the faulty part.
The main elements in the pump control unit are:
Due to the small capacitance of the capacitor, you can check it using a multimeter, which has a built-in C-meter with a limit of up to 20 µF. If the readings deviate significantly from the nominal value, the capacitor should be replaced; it is important to maintain the polarity of the connection and be sure to have its voltage tolerance. For a conventional single-phase motor, capacitors with a tolerance of up to 450 V are used.
The speed controller assembly is replaced with a new one. It is enough to disconnect it from the terminals, remembering the position of each pin and connect a new one.
The terminal block must be perfectly clean, dry and without signs of obvious overheating or burnt. If the above problems exist, then it should be replaced with a new one, the same or similar in the number of connections.
Popular models of circulation pumps are from the manufacturers Wilo, Ggrundfos, Dab. Not least due to their reliability. You can expect these pumps to break down within the warranty period only if the recommended operating conditions are violated. However, during the post-warranty period, Wilo often has problems with support bearings. Only replacing them helps.
Ggrundfos and Dab can “please” the impeller to become overgrown with scale for high-temperature heating systems, as well as silting of the stator cup. It is better to prevent these problems by installing a good filter and preparing the water. Otherwise, breakdowns are often justified by external problems.
The circulation pump fulfills the requirements for circulating the coolant throughout the entire heating system. The use of this device will improve the heating performance and increase the productivity of the system.
In installation options for pumping equipment, you can select pipes with a smaller diameter, which makes it possible to save money.
Read: about the use of circular pumps in a heating system.
Such pumps are divided into the following types: with a “dry” and “wet” rotor. In the first version, the motor of the pumping device is placed in a separate module, and the rotor rotates through a clutch.
There is a noise during operation.
Dry type equipment performs screening through the operation of a fan that cools the motor. This device is used in large houses. In them it is installed in an individual room.
Wet-type devices operate with a low noise level, since the rotor is immersed in a thermal fluid that cools the operating motor. This device can be placed near residential premises. The noise setting will not cause any inconvenience.
If the noise does not appear from the operation of the fan, then why is the heating circulation pump humming? The reasons may be:
In practice, the hum of a device can be caused by design properties, in other words, it is natural noise during operation, or a hum of a different nature that appears already during operation.
Malfunctions of the circulation pump may occur as a result of its heating.
Heating can occur while the motor is running; naturally, cooling is designed for this either with a heat carrier or with a fan. Excessive heating is possible from stopping the rotation of the rotor. In case of any problems, you need to disassemble the device; if it is impossible to remove the problem without outside help, contact a professional.
We hope that the publication was useful to you, and you will be able to remove the causes of the noise with your own hands. We will be grateful if you share the material on social networks.
Do-it-yourself circulation pump repair - step-by-step instructions
Circulation pumping devices are very popular among owners of private houses and summer residents. The range of pumping equipment is quite wide, but the general principles of the device are the same. Such equipment can stop due to minor breakdowns, for example: what to do? Should I take my broken pump to a service center? This costs money, and in many regions there are simply no service companies. Therefore, the economic owner of the house must know how to install.
To understand how to independently disassemble, maintain, and repair a circulation pump, you need to know its structure. Such equipment is arranged as follows:
After turning on the electrical circuit, the engine begins to rotate the rotor with the impeller mounted on it. Liquid is supplied to the central part of the pump. The blades rotate and throw water or other coolant towards the outside of the housing. Under the influence of centrifugal forces, the liquid moves and enters the outlet pipe of the pump.
There are currently two main types of circulation pump devices on the market.
In order to avoid having to disassemble and repair your equipment once again, it must be used correctly.
From time to time, preferably at least once a month, it is necessary to carry out an external inspection and check the quality operation of your circulation pump device.
There are a number of typical faults in circulation pumping devices that you can fix yourself. Each block will describe the symptoms of a malfunction, its causes and steps to do it yourself.
The reason may be oxidation of the motor shaft during prolonged inactivity of the pump. Troubleshooting instructions.
The next reason for this malfunction may be entry of foreign objects.
Also, the reason for the lack of rotation may be lack of power supply. To do this, we use a tester to check the presence of power at the terminals in the box and the correct connection of the electrical wires.
The main reason for this malfunction may be lack of power supply or insufficient voltage in the network. To eliminate it, you need to use a tester to check the voltage at the terminals and, if necessary, whether the device is connected correctly to the power supply.
Many electric pumps are equipped with a fuse. During power surges, it burns out and requires replacement.
The cause of this malfunction may be the deposition of limescale between the stator and the rotating rotor. The malfunction can be eliminated by dismantling the electric motor and cleaning it of limestone deposits.
The cause of this malfunction may be the presence of air in the heating system pipeline. To eliminate it, you need to bleed the air from the pipes. To automatically release air, it is recommended to install an automatic unit in the upper segment of the pipeline.
If a sharp noise is accompanied by increased vibration, it is recommended to increase the pressure at the inlet to the pumping device. Insufficient pressure can be compensated by increasing the coolant level in the system.
The cause of such a malfunction is usually severe wear of the bearing that ensures the rotation of the impeller. The malfunction is eliminated by replacing the worn bearing.
The cause of such a defect may be the wrong direction of rotation of the wheel with blades. The cause of this phenomenon is usually an incorrectly connected phase when connecting three-phase equipment.
Also, a decrease in pressure can be caused by increased viscosity of the coolant, then the impeller encounters too much resistance. To eliminate it, it is necessary to clean the filter on the inlet pipe from deposits, check the cross-section of the incoming pipeline and set the necessary pump adjustment parameters.
Most likely, the cause of such a malfunction may be incorrect connection of the wires according to the phases in the terminal box. The fuse on your pump may not be tight enough. Remove it and clean the clamps.
In order for your unit to operate smoothly throughout the cold season, it is necessary to carry out routine maintenance before the start of the heating season.
If, during a test run of the equipment, shortcomings of the pumping device are identified that cannot be eliminated without dismantling and disassembling it, you will have to perform the following operations.
Dismantling the pump before repair is especially necessary if your heating pipelines are made of metal-plastic. Repairs “on the fly” can damage such pipes.
When seriously repairing pumping equipment, it is necessary not only to dismantle it, but also to disassemble it. It is performed in the following sequence.
Self-repair of circulation pumps should be carried out only after the end of the warranty period or if it is impossible to obtain qualified technical assistance. A number of pump components are quite difficult to find on the open market. This is usually caused by the manufacturers' trade policies, so be prepared for the fact that in some cases it is cheaper to purchase new equipment rather than repair broken equipment.
To learn more about circulation pump repair technologies, watch the training video.
Noise during operation of the circulation pump is a cause for concern. If this is related to the heating system, you should figure out the cause of the increased hum as quickly as possible.
Increased noise may be due to the following reasons:
A thoughtful approach to choosing is the first thing to do. You should not chase a high-power pump, especially an air-cooled one. Any of those offered by the industry is capable of raising a column of water to a height of nine meters, which is quite enough for low-rise housing construction. Even if you are nearby, you may not hear his work. For this purpose, in some cases, a light indication of the on state is placed.
It is necessary to strictly comply with the requirements when installing a circulation pump with a “wet” rotor. It is cooled by the pumped liquid. Efficient performance is achieved with a horizontal engine rotor. Deviation from the rule leads to increased wear of equipment and noise.
Air in the system can appear for several reasons:
Periodic checking of connections, creating initial pressure in the system by installing a pressure tank, monitoring water quality and bleeding air through special technological plugs are sufficient conditions for getting rid of increased noise during pump operation.
Pumps are the most important part of forced circulation heating systems. Depending on their location in the heating system, they are responsible for the temperature of radiators or heated floors, forcing the coolant to circulate from the boiler through all heating circuits, thereby giving the residents of the house warmth and comfort. But then something bad happened - the pump broke. The eternal question immediately arises - what to do? Should I take it to a heating pump repair shop, try to fix it myself, or immediately buy and install a new circulation pump?
There is no definite answer to this question - it all depends on the nature of the breakdown and your desire to repair the heating pump.
We list the problems that can be fixed when repairing heating pumps at home, with your own hands.
Such defects in the operation of circulation pumps include:
Let's start with an analysis of the reasons why your pump does not work at all.
So, we have successfully repaired the heating pump and managed to get it working!
The next problem that happens with household heating pumps is usually formulated as follows: “... the pump seems to be working, but does not pump the coolant...”.
What's the matter here? And the problem is hidden in four types of possible problems.
After detecting and eliminating one of the listed malfunctions, the repaired heating pump should begin pumping coolant.
The next class of malfunctions is associated with low pump performance. What to do in this case? How to repair a heating pump?
The indicated tips should, in practice, help improve pump performance.
Now let's talk about what causes extraneous noise both in the coolant supply system to the heat exchanger and in the pump itself.
Noise when supplying coolant to the heat exchanger is usually due to two reasons:
Noise in the pump itself can almost always be explained by the following reasons:
Repair of a heating pump for various other malfunctions, such as, for example, wear of the shaft or leaks of coolant from the pump, on different models of pumps can be eliminated in various ways, from replacing rubber gaskets with installing new gaskets to processing on a lathe, which requires certain knowledge and skills from the user of heating pumps. It is from such factors as your wishes (whether you are satisfied with the pump that you currently have or would you like to change some parameters of its operation), the availability of financial capabilities, time and appropriate skills that determine what you choose - take it to a heating repair workshop pumps, try to repair it yourself or immediately buy and install a new circulation pump. However, even if you prefer a new pump, it would be a good idea to repair the old one too - so, just in case, keep it on the farm as a spare. This is rational, since not a single pump, even the most expensive and reliable one, is immune from breakdowns. Knowing the Russian climate, leaving yourself the chance to find yourself without a functioning heating system at the very peak of the cold weather would be extremely imprudent.
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