Grundfos DIY repair

In detail: grundfos do-it-yourself repair from a real master for the site my.housecope.com.

Grundfos pumps are most often used to optimize the circulation of the water supply during the heating season or in closed autonomous heating systems. They help to distribute heat evenly in the room and thus make more efficient use of energy.

Grundfos pump device.

These pumps are resistant to voltage surges and have overload protection. They are produced by a Danish company, which provides a guarantee for their quality and guarantees sufficiently high performance. These pumps can be used both at home and in industrial buildings.

However, if this equipment breaks down, the heating system will stop functioning and will remain cold until repairs are carried out.

The most common cause of pump malfunction is the formation of deposits that settle on the walls and, as a result, prevent the machine from starting. This violation can be corrected by doing the repair yourself. If you decide to purchase new equipment, it will be helpful to fix the old one. This way you can use it as a fallback.

For repairs you will need tools such as:

screwdriver;
scraper (made of wood);
hex wrench;
circle and polishing paste.

The first step is to remove all excess deposits from the shaft and rotor.

Since the main cause of pump failure is dirt build-up, the purpose of repairs is usually to clean the machine. To do this, you need to remove all unnecessary deposits from the two component parts - the shaft and the rotor. This can be done by first unscrewing the pump screws with a hex wrench and thereby disassembling the threaded connection that holds the motor and pump. Once you open it, determine how much rust has collected in it.

Video (click to play).

Depending on this, it can be removed with a cloth or scraper. In order to disassemble the washer, as well as the rotor with its impeller, it is enough to insert a thin screwdriver into the slots that are located around the support washer. You can determine for yourself how high the likelihood of new deposits forming on a given surface is. If it is smooth, there is much less chance of deposits forming. Now it can be processed with a grinding wheel.

After that, you need to inspect the stator. As a result of work, it can oxidize quite strongly, and in this case it can only be cleaned with a hammer.

For normal operation of the pump, it is necessary to polish its inner walls.

Special attention should be paid to the sensor. The dirt and rust that builds up on it over time often causes Grundfos pumps to lose their performance. As a result, their work may stop altogether. Therefore, the sensor must also be removed and cleaned of deposits. To do this, remove the cover from the control unit and disassemble the pump housing in two halves.

To remove the sensor itself, you must unscrew the screws using the wrench that comes with the pump. After loosening the screws, the sensor housing can be easily removed by hand. If this cannot be done due to settled dirt, you can pry it off with a screwdriver. Since this part is made of plastic, the manufacturer himself recommends cleaning it more carefully and using less aggressive materials. To do this, you can use a regular toothbrush.

In order for Grundfos to work again in normal mode, it is necessary to polish its inner walls.At the same time, the work can be facilitated if you use polishing tools, having previously fixed them in the drill chuck.

If a bearing is stuck in the pump, then it is necessary to disassemble it and try to turn the impeller.

In order to remove lime deposits, the system is filled with a solution of acetic acid and water, which are mixed in equal parts. Threaded connections can be sealed. This will help prevent pump leaks in the future. You can even use a bicycle tube pad for these purposes.

Sometimes the reasons for the pump stopping can be a jammed bearing, the lack of a water flow sensor, or a drop in pressure. To do this, it is not at all necessary to completely disassemble the pump in order to eliminate one of the above problems.

Try to simply switch the equipment to manual mode by removing the switch located on the junction box from the stopper and placing the handle in the middle position. This will allow the pump to run even when the tap is closed. But if this did not help him turn on, then it is necessary to disassemble the pump and try to turn the impeller. If it does not scroll, the pump cannot be repaired.

If the pump works only in manual mode, the cause of the breakdown is the flowing water sensor.

The breakage can be eliminated by replacing the sensor itself. Sometimes the pump stops working after turning off the water due to the fact that air accumulates in it. In this case, you can lower it by turning the central screw.

After completing all these operations or when completely cleaning the pump, it must be reassembled. This is done in reverse order.

If none of the above actions led to the resumption of the pump's operation, the breakdown may consist in the failure of the winding of its motor or capacitor. Such a malfunction requires replacement of spare parts, which can only be provided by a service center. Otherwise, the only way out is to replace this device. In European countries, the average service life of these pumps is about 5 years. However, the water quality in Europe is better, so the lifespan can be shortened by a year or two.

Any pump is susceptible to damage. It is necessary to take into account their constant contact with various kinds of liquids. Therefore, even pumps from the well-known Danish company Grundfos are not insured against stopping due to failure. It is the water that causes the loss of performance. Depressurization due to worn out glands or seals can create a breakdown in the insulating components of the pump. To avoid trouble, you should periodically inspect the pump.

It is better to entrust the repair to professionals. However, no one says that in some cases, some types of restoration work can be carried out at home. More on this later.

Before providing first aid to the pump, you should familiarize yourself with the most common causes of pump failure:

The use of the pump for purposes not foreseen by the manufacturer.
Incorrect installation of the unit.
Voltage surges - from low to above required.
Pumping liquids containing large solids.
Ignoring the correct fixation of the cable.

The grundfos pump can also fail due to the failure of its pump. In this case, the only correct solution would be to completely replace the broken part of the device. Do not forget that in the process of replacing any parts of the pump, it is almost completely disassembled. The main task will be not only to assemble everything in the reverse order, but also during the assembly process not to harm the pump with anything else.

Read also: DIY car headlight repair

The best repair option would be to contact a service center, where the restoration of the device's performance and maintenance is always at a high level.With the help of the necessary tests and stands, the following will be carried out in a quality manner:

breakdown diagnostics;
replace broken components with original ones;
will carry out post repair tests.

Test benches provide the ability to:

check hydraulics indicators;
measure the resistance level of the insulating material of the electric motor;
test the cable supplying power to the motor.

Using a variety of tools of the service center, it is easy to:

replace the rotor of the electric motor;
change worn-out bearings that require pressing out;
change the top cover of the engine;
clean the pumping part of the pump from contaminants.

The pumps are taken out of working condition, various deposits settling on the walls. It is they who prevent the device from starting. Your hands will always help to get rid of the problem, even if they are not golden.

Getting down to the crucial moment, prepare the necessary working tool. You will need:

hex key;

wooden scraper;

polishing paste;

polishing wheel;

cross and flat screwdrivers;

hammer (medium and small).

The primary repair task will be to clean the rotor and shaft from deposits accumulated on them. Armed with a hex wrench, unscrew the screws on the pump. This brings us to the threaded connection holding the pump and its motor. Such repair of grundfos pumps is not the pinnacle of genius. After opening, you will be convinced that there is an impressive amount of rust.It can be easily removed with a scraper or strong cloth. A small, flat screwdriver will help to get to the rotor and its impeller. It must be positioned in the grooves along the diameter of the support washer. The surface that has opened will need to be carefully sanded, which will eliminate the possibility of new dirt adhering. To do this, use a previously prepared grinding wheel.At this stage, you can proceed to inspect the stator itself. Its main enemy is oxidation. The working tool here will be a hammer, with which it is necessary to tap the surface and knock down the deposits by vibration.Rust in tandem with dirt is favored by a controlled pressure sensor. In this context, the maintenance of grundfos pumps is extremely important for stabilizing the functioning of the device and its operation in general. To do this, you will need to disassemble the pump into two parts by removing the cover of the unit.The sensor can be removed by hand using the keys specially made at the factory, which are included in the standard package of the product. In some cases, it is required to lightly pry it off with a screwdriver, when the accumulated dirt impedes the removal process. The manufacturer requires it to be cleaned with soft tissues without undue effort. The best option would be to use an ordinary toothbrush.Danish pumps are always efficient if they are repaired and serviced in a timely manner. Therefore, special attention should be paid to polishing the inner walls. To eliminate the laboriousness of the process, the work is facilitated by the use of polishing tools, which are most convenient to use fixed in the drill chuck.Bearing wedging is also possible. To break it, sometimes it is enough just to turn the impeller. Limestone deposits are no less annoying. Cleaning takes place by means of preparing a vinegar bath. You will need to mix this acid with water in equal proportions. Try to pay attention to the threaded connections as well. Seal them if possible using a bicycle tube to create spacers.Other breakdowns are not excluded. Stopping the pump is possible due to:

seized bearing;

inoperative sensor for the presence of a water flow;

lowering the pressure.

In such cases, you should not disassemble the pump to the smallest detail. Just put it in manual control mode.To do this, remove the switch, which is locked and located on the pump distribution box. Such actions can make the pump work even if the drain valve is closed. Otherwise, you will have to turn the impeller manually. If you fail to rip it out of place, then a complete replacement of the element will be required.Functionality is guaranteed by regular servicing of grundfos pumps. Sometimes there are exceptions to the rule. If the device fails to operate in the process automation mode, but works on manual control, try replacing the sensor for fixing the movement of water. The unit may have stopped listening to commands through the accumulated air in the system. Bleed it off by turning the center screw.Problems are possible in any pumps, even circulation ones. Once you have decided to personally eliminate any potential problems, always try to assemble the pump in such a way that after the assembly is complete, there are no unnecessary parts left on the workbench. Stick to the reverse order of assembly.

Pump manufacturers such as Grundfos produce quality pumps that are characterized by high performance and long service life. But even high-quality equipment is susceptible to breakdowns in the event of non-compliance with the norms of use or when periodic maintenance is not carried out. As a result - partial or complete cessation of the functioning of the apparatus.

Grundfos pumps are usually repaired by specialized workshops, which charge a substantial fee for their services. Moreover, the problem itself is not always worth the money spent. The solution may be to repair the Grundfos pump with your own hands, which is quite possible with certain knowledge.

The repair of Grundfos pumps depends largely on the type of pumping device. Depending on the type of device, the design, the most probable malfunctions and the way of their elimination differ. Among the main series of pumping devices manufactured by Grundfoss, the following stand out:

borehole pumps of the SQ, SQE, SP series;
drainage and well devices Unilift KP, cattle;
circulating devices for heating UPS, UPSD, ALPHA2, ALPHA3;
sewerage system Sololift and Sololift 2 WC 3;

Range of pumping equipment Grundfos

Each individual device implies its own peculiarities of repair and maintenance.
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Downhole tools such as SQ and SQE operate at great depths, where the bottom water can contain a high percentage of abrasives and silt. Therefore, the most common failure in such devices is contamination of the impeller and failure of the check valve. As a result, the device may not turn off after the end of work, or there is no pressure in the line. The solution to the problem will be to disassemble the pump and replace the check valve. In this case, it will not be superfluous to clean the entire working chamber.

Another common problem with the SQE series is air ingress into the system. As a result, the pressure level is disturbed, and the device turns on and off by itself. In this case, the power is turned off, the filters and the impeller are checked for contamination, then air is released from the line.

Also, a rather serious malfunction of a pumping device of the SQE type is increased vibration during operation. Such a problem can lead to too much silting of the source, which can make it unusable. Vibration occurs when the impeller is not centered. This happens when the fastenings on the housing are unevenly tightened, or the shaft bearing has become unusable. The solution is to replace the bearing and adjust the rotor inside the chamber using a ruler.

To solve any of the above problems, it is necessary to disassemble the apparatus. The procedure is carried out in the following stages:

The device is firmly clamped in a vice. It is advisable to clamp with pipe halves so as not to deform the body.
Further, VD-40 is injected into the thread area, after which you can gently turn it. The thread is often clogged with clay and sand, which greatly complicates the unwinding process.
The rotor is removed from the working chamber.

Such disassembly is sufficient for cleaning the pump chamber and replacing the main components. The motor chamber is designed in such a way that it is not possible to disassemble it. Therefore, in case of damage to the motor winding, control electronics or electrical cable, the pump must be returned for repair.

After the device is disassembled, it is necessary to clean the impeller, bearing, valves in running water, and if necessary with a brush. You should also carefully inspect the mechanical seal between the working chamber and the engine compartment. There should be no obvious damage or tears on it. After the cleaning and replacement of components is done, the device is assembled and connected to the mains.

The device of the pumping station Grundfos

Assembly is carried out upside-down. In this case, the important points are the uniform fixation of both mounts on the body, correct thread adjustment, centering of the rotor and its fixation in the socket. If the filter at the suction ports is damaged, it must be replaced to prevent further contamination.
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The Unilift KP and KRS series are designed for pumping melt water, sewage, septic tank contents, and drainage of swimming pools. At the same time, the simple design of such devices makes it easy to repair the Grundfos pump with your own hands.