DIY water pump repair wilo

In detail: do-it-yourself repair of a wilo water pump from a real master for the site my.housecope.com.

Forced movement of water in water supply and heating systems is provided with the help of pumps. Reliable and efficient operation of the pump, when heating premises, supplying cold and hot water, will satisfy all domestic needs, and in some cases industrial needs.

Normal operation of a Wilo pump is possible only if the operating rules are observed, timely maintenance (preventive work), high-quality diagnostics and repairs.

In order to avoid premature repair of Wilo pumps, the following should be adhered to:

exclude idling (in the absence of water in the system);
do not block the water flow when the pump is on;
set the operating mode in accordance with the minimum and maximum capabilities of the equipment;
follow the manufacturer's recommendations on the permissible pressure in the system;
do not allow heating of the coolant suitable for the pump over 65 О С;
avoid long downtime;
use filters to clean the water circulating in the system.

The range of Vilo pumps

If these rules are followed, the pump will make a uniform sound and maintain a stable head, which is evidence of its normal operation. Most pumps operate without repair for 5 years or more, until the main elements are completely worn out, provided that all operating rules have been observed.
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In order not to require repair of the Vilo pump, it is necessary to carry out periodic preventive maintenance. Simple maintenance of the device can be done by hand, without resorting to the services of specialists. To do this, inspect the pump at least 4 times a year and, if necessary, clean it. As practice shows, cleaning is necessary after 2-3 years of operation, depending on the quality of the coolant and the general conditions under which the heating and water supply systems operate.

Video (click to play).

Checking the water jacket of the rotor

When inspecting the equipment, be sure to pay attention to the following points:

no leaks at the joints;
efficiency of grounding;
absence of extraneous sounds during device operation (clanking, knocking);
lack of vibration;
system pressure in accordance with technical standards;
dry and clean body of the device.

Wilo pumps, in most models, are reliable and do not require regular repairs. But prophylaxis, provided that the warranty period has expired, can be carried out independently.

spanner key;
Phillips screwdriver;
flat screwdriver;
cleaning brush.

Before dismantling the pump, water is drained from the system or the area is closed off for dry disconnection of the device. Then the pump is removed, and the following actions are performed:

A spanner wrench is used to unscrew the bolts (4-6 pieces) connecting the electric motor housing and the shell of the pumping part.
Removing the shell will open access to the drain holes and the impeller will remain on the engine rotor.
A narrow flat-blade screwdriver pushes on the jacket separating the engine compartment and the impeller, as a result of which the rotor shaft and impeller will come out of the stator glass.

Dismantling the circulation pump

After completing these steps, the main disassembly is completed and the inner surfaces of the shell, impeller and rotor are cleaned from scale or dirt deposits.

The surfaces are cleaned with a hard polymer brush with a small amount of cleaning agent containing hydrochloric acid.

In case of strong (stuck) dirt, it is permissible to use zero sandpaper.

The main malfunctions of Wilo pumps are the wear of the thrust bearings. If such a factor is identified, it is difficult to replace them with your own hands, so it is better to contact a service center.

All gaskets and seals are inspected for cracks or breaks prior to reassembly. But since the pump has already been disassembled, it is advisable to replace them with new ones.
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In cases where vibration appears during the operation of the device, extraneous noise occurs, the pressure in the system changes, you should determine their cause and, if possible, eliminate the malfunctions yourself.

When switched on, the pump hums, but the shaft does not rotate:

the shaft has jammed due to prolonged downtime. Remove the protective cap on the motor housing and turn the shaft with a flat screwdriver;
if foreign objects get in, disassemble the pump and clean the impeller, after that replacing the cleaning filter, which is installed in front of the device;
power supply problems (insufficient mains voltage).

When turned on, the device does not work:

there is no mains voltage. The electrical wiring and protective automatics are checked;
fuse blown. Replaced with a new one.

Self-shutdown of the device after a short period of operation:

Rules for installing and connecting the circulation pump

accumulation of limescale in the stator glass. The glass and the rotor of the electric motor are being cleaned.

The pump makes a lot of noise during operation:

dry operation in the presence of air in the system. Release the air and make sure the pump shell is filled with liquid;
cavitation. Pressurize the fluid line.

Excessive vibration of the pump:

critical state of support bearings with severe wear. Bearings must be replaced.

Reduced head and flow compared to manufacturer specifications:

power failure or phase change, which leads to a drop in power or reverse rotation of the impeller. Phase check (three-phase motors) and capacitor replacement (with single-phase power supply);
the pipeline has a high resistance to fluid movement (hydraulic resistance). Clean (replace) filters, check shut-off valves, increase pipe diameter if necessary.

Automatic shutdown of the pump by an external protection system:

malfunction of the electrical components of the device. Check connection terminals (oxidation, short circuit), capacitor (replacement), control unit.

It is better to have your faulty pump repaired at a service center if the warranty period has not yet expired. Some models are non-collapsible or partially disassembled, which implies repair work in the form of replacing entire blocks or the entire device.

Testing the electrical box of the circulation pump

In the absence of a guarantee and the possibility of disassembling the pump, minor repairs are carried out independently.

According to the above signs, the causes of malfunctions are eliminated, and repairs are carried out if the design of the pump allows it to be disassembled.

Operating elements of the control unit that can cause the pump to fail and must be replaced:

capacitor;
connection block (terminals);
speed regulator.

Since the capacitor has a small capacity, its performance can be checked using the C-meter, which is built into the multimert. If a discrepancy with the nominal values is found, this part should be replaced with a new one. It is important not to reverse the polarity of the connection and check the voltage compliance. In a conventional single-phase electric motor, capacitors are installed that are allowed to be connected to the network up to 450 V.

If the speed controller breaks down, it is replaced with a new one, observing the correct connection of the terminals.

The terminals must always be clean, dry, and free from signs of overheating and carbon deposits. If the above problems are identified, they should be replaced with new ones, similar or the same, if possible, connection.

During post-warranty operation, problems with support bearings are possible. It is better to replace them in a specialized workshop.

To prevent the formation of scale on the impeller and silting of the stator glass, you should install high-quality filters and use the prepared liquid in closed heating systems. Subject to these conditions, the pumping liquid pump will operate under ideal conditions and will not cause problems with repairs for a long time.
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The heart of any heating system is the circulation pump, which is responsible for the forced movement of water in the system. In order to minimize energy costs and at the same time create comfortable temperature conditions in the living room, they buy Wilo pumps.

Ensuring their efficient and reliable operation, extending their service life is carried out by observing the operating rules, timely maintenance. If the owner ignores these requirements, equipment malfunctions will inevitably occur. Their elimination in the case when the warranty period has expired is often done by hand.

Vilo pumps significantly increase the efficiency of the heating system and the heat transfer of the coolant. Their use makes it possible to use pipes with a smaller cross-section when assembling the line, which will reduce fuel consumption, reduce the emission of carbon dioxide, and make it possible to achieve savings without losing the quality of functioning. This is achieved through a well thought out and developed design, designed for continuous operation.

Checking the water jacket of the rotor

The Wilo pump consumes no more than 250 W per day, the operation is silent, since there is no fan and similar technical elements that produce noise. There are two types of circulation equipment on sale - with a dry and a wet rotor. The latter are used in the installation of heating systems, usually inside small buildings. The difference also lies in the power and volume of the pumped medium. The weakest model is able to make the heating system more efficient on an area of 200 sq. M.

The powerful one is designed for heating buildings with an area of up to 1000 sq.m. Both the one and the other unit have the most simplified design and small dimensions. The technical characteristics regarding the pressure head allow water to be raised from 8 meters at a flow rate of 5 m / h.

Distinctive features are the strength and corrosion resistance of the Wilo pump material. For example, the body is cast from cast iron, the shaft located inside it is made of stainless steel. Its fastening is possible thanks to graphite bearings. The water flow rate is equipped with a three-stage adjustment.

The permissible temperature of the coolant in household products should not exceed + 110 ° С; for industrial products, the temperature limit is increased. As for the working pressure, the units used in everyday life are capable of withstanding 10 bar, and industrial units - 16.

The system is controlled by automation. Some models of circulators have a thermostat. The functions of the mechanism are displayed on the liquid crystal display. You can also control the shaft speed by manual switching. The connection of the device is simple and quick, which is facilitated by the presence of springy terminals. Voltage surges are not terrible for the pump, since the motor and rotor have a multi-stage protection system.
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In order to avoid premature repair of Wilo pumps, the manufacturer encourages adherence to the following:

Do not allow the device to idle when there is no water in the system. Dry running destroys insulation, disrupts motor cooling and destroys all equipment.
The operating mode is set strictly in accordance with the maximum-minimum capabilities of a particular model.
When the pump is on, the heating medium flow must not be shut off.

Dismantling the circulation pump

If these rules are observed, it will be characteristic for the pump to maintain a stable pressure, and the sound emitted during operation will be uniform and quiet. Most of the pumps do not need to be repaired within 5 years from the moment they were put into operation. It is required only in case of complete wear of the main components or force majeure circumstances that caused the device to fail.

Prevention is another type of periodic measures, the implementation of which insures the pump and its elements from premature breakdowns. At the same time, simple maintenance is carried out with your own hands, without the intervention of a specialist. For this, a visual inspection of the external and internal parts of the unit should be carried out annually at least 3-4 times, and it should be cleaned if necessary.

Practice shows that cleaning becomes mandatory after 2-3 years of work. The quality of the coolant, the general conditions under which the heating system operates, affects the performance of cleaning procedures.

For prevention, it is necessary to prepare a Phillips and flat screwdriver, a spanner wrench, a cleaning brush. Inspection requires disassembly, during which you will find the main components of the hydraulic structure: housing, impeller, motor shaft, rotor, terminal box, propeller and the motor itself. Pay attention to the following nuances:

efficiency of grounding;
absence of leaks at the joints;
pressure value in accordance with technical standards;
lack of vibration and extraneous sounds (knocking, clanking);
condition of the case. It must be clean and dry;
the pump should not get very hot;
the amount of grease on bearings, flanges and moving parts must be sufficient;

Also make sure that the terminal box cables are free of moisture and that they are securely in place, that the gaskets provide a seal, and that the connections to the mains are firm. Before dismantling the device, water is drained from the system, the section of its entry is blocked, after which the pump is removed.

Rules for installing and connecting the circulation pump

The 6 bolts connecting the shell of the pumping part and the motor housing are unscrewed with a spanner wrench. When the shell is removed, the drainage holes will be accessible. The impeller remains on the motor rotor. With the help of a narrow flat-type screwdriver, the jacket is pushed off, which serves for the impeller and motor compartment. The actions taken will remove the rotor shaft and impeller from the stator glass.

At this stage, the inner surface of the shell, the rotor and the impeller are cleaned from dirt deposits or scale. A stiff polymer brush and a small amount of cleaning agent with hydrochloric acid will help. It will be useful to check all seals and gaskets for cracks, if found, replace them with new ones.
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Read also: DIY gur repair

The circulation pump needs cleaning

By the way the pump works, sound, vibration or a change in head, outlet pressure, it is necessary to accurately determine the malfunction and eliminate the cause.

Circulation pumps of various types are often used today in country houses and summer cottages, which makes it possible to make the operation of autonomous heating systems more efficient and at the same time save on energy resources. Meanwhile, if such a hydraulic machine fails, the entire heating system ceases to function, which puts its user with a choice: use the services of qualified specialists or repair the heating circulation pump with his own hands.

Dismantling the circulation pump

The reasons for the breakdown of circulation pumps, the types of which differ from each other in certain design features, are associated both with non-compliance with the rules for operating such equipment, and with the quality of the coolant, drops in the power supply network, as well as with a number of other factors. Before deciding on an independent repair of the circulating pump, you should understand well the design and principle of operation of such a device, which will allow you to establish the exact cause of its failure and eliminate it.

Without knowing the device of the circulation pump, you will not only be able to repair such a hydraulic machine, if necessary, but also engage in regular maintenance. The design of circulation pumps is:

a body made of stainless steel or non-ferrous alloys;
an electric motor, the shaft of which is connected to the rotor;
directly the rotor itself, on which the wheel with blades is installed - the impeller (its blades, which are constantly in contact with the pumped medium, can be made of metal or polymer materials).

Circulation pump design

The circulation pump operates, regardless of its design, according to the following principle.

After the electric current is supplied, the shaft of the drive motor begins to rotate the rotor on which the impeller is installed.
The heat-transfer fluid entering the inner part of the pump through the suction branch pipe is thrown by the impeller and centrifugal force to the walls of the working chamber.
The liquid, which is subject to centrifugal force, is pushed into the discharge pipe.

As mentioned above, depending on the design features, the circulation pump for heating can be of different types. So, devices with a rotor are distinguished:

In private houses, the most commonly used circulation pumps are "wet" type

For circulation pumps of the first type, which are used mainly for equipping domestic heating systems, the rotor is constantly in a liquid medium. This not only contributes to the lubrication of the moving parts, but also to their efficient cooling.The main advantages of this type of equipment include:

low noise level during operation, since the water, in which all the moving elements of such a device are located, perfectly absorbs vibrations;
ease of installation (such pumps simply cut into the pipeline), maintenance and repair.

Meanwhile, pumps with a "wet" rotor, if we talk about their shortcomings, are not very efficient, can be installed only in a horizontal position and are very critical of the lack of liquid in the heating system.

Pumps with "dry" rotor are installed in separate boiler rooms and are used in systems that heat large areas

The drive motor of pumps with a "dry" rotor is placed in a separate unit. Rotation from the motor shaft is transmitted to the impeller by means of a special coupling. Unlike devices with a "wet" rotor, pumps of this type are characterized by a higher efficiency (up to 80%), but also by a more complex design, which somewhat complicates the procedures for their maintenance and repair. Circulation pumps with a "dry" rotor are cut into the pipeline and their body is fixed to the wall, for which a special console is used.

In order not to face situations in which the circulation pump installed in the heating system will require repair, it is necessary to strictly follow the rules for operating such equipment, which are as follows.

If there is no water in the pipeline, it is impossible to start the circulation pump.
The value of the generated water pressure must be within the characteristics specified in the technical passport of the circulation pump. If the device produces a reduced or, conversely, increased water pressure, this can lead to its rapid wear and, accordingly, failure.
During the period in which the heating system is not used, the pump must be turned on for circulation at least once a month for a quarter of an hour, which will prevent oxidation and blockage of its moving parts.
It is very important to ensure that the water temperature in the heating system does not exceed 65 °. In water heated to a higher temperature, a precipitate begins to actively form, which, interacting with the moving parts of the hydraulic machine, contributes to their active wear and, accordingly, the failure of the entire device.

It is necessary to inspect the circulation pump and check the correctness of its operation on a monthly basis. Such measures make it possible to identify malfunctions in the operation of equipment at the initial stage and promptly take appropriate measures.

Periodic inspection of the circulation pump will significantly reduce the likelihood of its failure during the heating season.

Checking the circulation pump for correct operation includes such actions as:

switching on the hydraulic machine to the operating mode and checking the level of noise and vibration generated by it;
checking the pressure (pressure level) of the coolant created in the discharge pipe (as mentioned above, the pressure of the liquid must be within the values given in the technical data sheet);
control of the degree of heating of the engine, which should not be too high;
checking for the presence of grease on the threaded connecting elements of the pump and applying it if it is absent;
checking the presence and correctness of the grounding of the body of the hydraulic machine;
checking for leaks both on the pump casing and in the places where it is connected to the pipeline (if leaks are present in such places, it is necessary to tighten the threaded connections and check the integrity of the installed gaskets);
Inspection of the terminal box and check if the wire is fixed in it (in addition, it is necessary to check whether moisture gets into the terminal box, which is unacceptable).

The main reason for the rapid wear of friction bearings in pumps is considered to be the increased contamination of the coolant.

It is possible to single out several of the most typical malfunctions for circulation pumps, which are quite realistic to fix with your own hands. Such malfunctions can be identified by their characteristic signs, without even disassembling the pump and without using complex diagnostic equipment.

A situation where the pump is noisy but the impeller is stationary is often caused by oxidation of the drive motor shaft. This can happen due to the fact that the hydraulic machine has not been used for a long time. To repair the heating pump with your own hands with such a malfunction, you must perform the following steps:

disconnect the power supply;
drain all water from the pump and the adjacent pipeline;
by unscrewing the corresponding screws, dismantle the drive motor together with the rotor;
resting on the working notch of the rotor with a hand or a screwdriver, turn it by force, moving it from a dead center.

Disassembled circulation pump

The pump will make noise, but it will not work even if a foreign object gets into its inner part, which blocks the rotation of the impeller. To repair the circulation pump in such a situation, do the following:

turn off the power supply;
drain water from the pump and the adjacent pipeline;
disassemble the pump according to the above scheme;
remove a foreign object;
a strainer is installed on the inlet pipe.

This is how the body of the circulation pump looks from the inside.

If the circulating pump is turned on, it does not make noise, but does not work either, there may be problems with the power supply. To identify the cause and eliminate such a malfunction, disassembly of the circulation pump may not be required: using a tester, they check the level and presence of voltage at the terminals of the device. In many cases, to eliminate such a malfunction, it is enough to correctly connect the pump to the power supply.

If there is a fuse in the design of the circulating pump, then it could burn out during a voltage drop in the mains, which can also be the reason why the heating pump does not work and does not make noise when it is turned on. To restore pump operation, simply replace the blown fuse.

Armed with a tester and a schematic diagram, you can find more serious breakdowns in the electrical part of the pump, for example, burned out windings

In the event that a layer of lime deposits has formed on the inner surface of the stator, the operating pump will periodically stop. To solve this problem, it is necessary to disassemble the pump and clean all its internal parts from lime deposits.

The reason for the loud noise of the equipment when pumping liquid can be the presence of a large amount of air in the pipeline. To eliminate such a problem, it is enough to bleed air from the pipes. In order not to face this in the future, you can install a special unit in the upper part of the heating system circuit, which will automatically release air from the pipeline.

If the housing of the hydraulic machine vibrates strongly when pumping the coolant, this may indicate that the bearing that ensures the rotation of the impeller is badly worn out. Repair of a circulation pump for heating in this case consists in replacing a worn bearing.

End graphite bearing of the "Grundfos" pump

Among the reasons for the discrepancy between the fluid pressure and the standard values at the outlet of the centrifugal pump are the following.

The impeller is rotating in the wrong direction.
The phase conductors in the terminal box are incorrectly connected (with three-phase connection).
The viscosity of the heating medium used is too high.
The filter installed on the suction line is clogged.

The specified issue is corrected according to the cause that caused the issue.

The reasons for such a malfunction may be incorrect connection of the phase wires in the terminal box, bad or oxidized contacts in the safety assembly of the device.

To repair the electronic component of the pump, you will need basic knowledge of electrical engineering.

This is another nuisance that occurs quite often during the operation of such equipment. Why is the circulation pump heating up? The reasons may be different, but such a situation always indicates that your equipment is operating under increased load.

Thus, many situations in which the circulation pump does not work or does not work correctly can be dealt with on your own, without resorting to the services of qualified specialists and without purchasing expensive spare parts and components for repair.

Before the start of the heating season, in order not to subsequently face the failure of the circulation pump and its repair, it is necessary to properly prepare the device for a long period of intensive work.

It is necessary to check the correctness of the pump tapping into the pipeline, referring to the arrow on the housing and the impeller rotation indicator. When installing a new pipeline for installing a circulating hydraulic machine, it is better to choose a section directly in front of the boiler, where the risk of air congestion is minimized.