Error F21 (E21) of the Bosch washing machine: what does the code that the Bosch washing machine produces mean, how to detect the problem and fix it, how to reset it?

Bosch washing machine code E21 - what is it?

The Bosch washing machine signals the impossibility of rotating the drum with error f21 (e21) on the control panel display.

In a situation where the washing machine is not equipped with an information display, you can find out about the problem that the drum rotation is blocked by the blinking indicators:

The Bosch Classixx model signals error e21 by flashing the “Rinse” mode indicator (second light from the bottom).
The Bosch Maxx 4 model reports an error by flashing the “Ready for use” and “End of washing” indicators (first and third from the bottom).
The Bosch Maxx 5, 6 or 7 model indicates a malfunction by simultaneous flashing of the spin speed indicators (1000, 800) and the Rinse mode indicator.

If error e21 occurs, the washing machine should be turned off immediately. Otherwise, when diagnosing and fixing the problem, there is a high risk of electric shock.

Description

When using Bosch equipment, error F21 may appear not only in the form of a code of letters and numbers. On Bosch models that do not contain a display, the fault is indicated by a combination of flashing indicators located on the control panel.

Flashing indicators allow you to recognize a number of errors. Technicians who have extensive experience working with similar washing machines determine error code F21 offhand. But an ordinary user can also identify an error using indicators. To do this you will need a table of error codes.

On Bosch washing machines without a display, error F21 is displayed as follows. The washing machine freezes and does not respond to button presses. Also, the machine does not respond to turns of the program selector. At this moment, 3 lights on the control panel flash or light up at once: rinse, 800 revolutions and 1000 revolutions.

You can see how the F21 code is displayed on Bosch machines without a display in the picture below.

Older models spin at a maximum of 800 rpm. In this case, the rinse, 600 and 800 rpm indicators will light up.

Code F21 has a fairly simple interpretation. However, this does not mean that determining the causes of its occurrence will be easy.

Code F21 indicates that the drum does not rotate in Bosch equipment. Before displaying code F21 on the control panel, the Bosch washing machine attempts to start the drum. And if this fails, then the corresponding code F21 appears.

This error may appear if the following malfunctions occur:

tachometer failure. With this malfunction, information about the speed of the washing machine motor is not sent to the control module. As a result, it stops the Bosch machine from working, and then displays error code F21;
engine malfunction. A broken motor cannot rotate the drum. Therefore, after several unsuccessful attempts to start the engine, the module displays error F21;
The circuit supplying the tachometer or motor has broken. This malfunction occurs when the wiring is broken or the contacts are oxidized. The motor and sensor are in good condition;
During the washing process, a foreign object may enter the tank of a Bosch machine and cause the drum to jam.

Also, code F21 may appear when the voltage in the supply network drops.

Call the master

In a situation where attempts to independently resolve error e21 were unsuccessful, a service center technician will help restore the functionality of the Bosch washing machine. It is enough to leave a request by phone or on the website of a specialized company (the coordinates are easy to find on the Internet). The application indicates the model of the washing machine, the year of manufacture of the device, and the essence of the problem.

A professional technician will carry out diagnostics, quickly determine the cause of error E21, and eliminate the malfunction. On average, the cost of services to eliminate the E21 error varies from 1,500 rubles. up to 5000 rub. (urgency of the order increases the amount due).

To avoid falling for scammers, before leaving a request, it’s a good idea to find reviews from those who have already used the services of the selected specialist. You cannot pay for repairs that have not yet been completed! Otherwise, there is a high risk of being left without money and without a repaired washing machine.

Motor malfunction

Models of Bosch washing machines assembled in Russia quite often experience serious problems with the motor. The simplest problem is faulty brushes.

It should be noted that brushes on commutator motors are often worn out. The technician can easily replace them. It will, of course, be more difficult for a non-professional to cope with this task. However, this work is considered quite simple and can be done independently.

The situation is much more complicated if current leaks from the motor of the Bosch device to the housing. Also, several turns of the winding may be broken in the motor. As a rule, in such cases it is necessary to completely change the engine. It will be cheaper than repairing an old motor. But first you need to check the current leakage.

To do this, you need to check the housing for leaks using a multimeter. If there is no leakage, each turn of the winding must be checked. This is necessary to detect a breakdown.

This work is quite labor-intensive and painstaking. However, after it is completed, it will be clear whether the motor has failed or not.

How can I prevent future breakdowns?

prevent problems that provoke error e21 :

Before loading into the drum, the pockets of dirty clothes must be checked for the presence of foreign objects, buttons and other small accessories are checked for strength.
Small items of clothing, as well as underwear and socks are washed in special mesh bags.
Connecting the washing machine through a special voltage relay will help avoid breakdowns caused by a sudden surge in voltage in the network.

Strict adherence to all the manufacturer’s recommendations specified in the passport of the household appliance will help you operate the washing machine for as long as possible without repair.

What does error F21 mean?

If a Bosch washing machine shows error code F21, experts recommend immediately disconnecting the unit from the power supply. Then you need to use the help of a technician who can repair the faulty device. It is not recommended to try to eliminate the causes of the malfunction on your own, but you can always find out what such an error means.

The machine can display this code not only in the form of letters and numbers. As described at the beginning of the article, models without a display will report a problem using a combination of blinking indicators located on the control panel. You can determine an error without a display using the following signs:

Important! The main reason for the appearance of code F21 means that the drum is not spinning in the equipment.

At first, the unit will try to start it on its own, but after unsuccessful attempts it will show an error.

There may be several reasons for this phenomenon.

Important! You cannot continue to use the unit if error F21 appears.

Adviсe

Often code e21 is a signal that the washing machine drum is overloaded . To understand whether this is true, you need to unplug the power cord from the outlet, manually drain the water, reload the drum, and start a new wash cycle.

Before testing the tachogenerator with a multimeter, the sensor must be carefully cleaned of oxide deposits, otherwise the test data may be incorrect.

After the cause of error e21 has been eliminated, additional steps must be taken to reset the error. How to reset the code? To do this, set the selector switch to the “Off” position, then “Spin”, hold down the drum speed switch button for a few seconds, set the selector knob to the “Drain” mode, and press the speed switch button again for a couple of seconds.

When the cause of error F21 is a malfunction

Almost always the cause of this error is wear on the motor brushes. More rare breakdowns are the control board, motor or tachometer.

Motor brushes - from 1600 rubles*

Over time, the motor brushes wear out, and the washing machine stops spinning the drum: first on the spin cycle, then on any mode. The brush stubs do not make good contact with the commutator, which can cause the machine engine to spark. The washing machine drum may also twitch. To fix the damage, you need to replace the brushes.

Control module - from 2300 rubles*

With such a malfunction, the washing machine drum rotates only in one direction, jerks or does not rotate at all. In the control unit, the following may fail: reverse relay (the drum rotates only in one direction), triacs, resistors and other radio elements in the motor control circuit

Firmware for the control unit - from 1900 rubles*

Firmware is the memory of the module, which contains all the operating algorithms of the washing machine. When it goes wrong, the washing machine behaves unpredictably, including the drum may not spin. To fix the problem, the technician unsolders the memory from the control board, reprograms it on a special device and solders it back.

Motor - from 2300 rubles*

There is a break or short circuit in the rotor or stator windings, so the motor does not work at all or hums, but does not rotate the drum. When shorted, it can knock out the machine in the apartment. The technician checks the windings with a multimeter, and if they are faulty, replaces the motor with a new one.

Tach sensor - from 2300 rubles*

In Bosch washing machines with a commutator motor, the tachometer is mounted on the motor shaft, which is called the rotor. The sensor records the rotation speed of the motor and transmits them to the control module. When it fails, the washing machine “does not understand” at what speed the drum rotates and goes into error F21 or E21.

Wiring or contacts in the engine circuit - from 1800 rubles*

It is necessary to check all the connectors of the cable with wires that connect the motor to the control unit. Perhaps they have oxidized, rotted or burned out. The wiring along its entire length is also checked. Perhaps the cable was rubbed due to vibrations during operation of the Bosch washing machine or it was damaged by rodent pests (mice, rats). In such cases, the technician twists the wires or changes the cable completely. The contacts are cleaned, soldered, or the entire contact group is changed.

*Spare parts are not included in the price and are paid additionally

Does your Bosch washing machine display F21 or E21 and not spin the drum? Call our workshop. We will come to your home, determine the cause of the breakdown and fix the problem on the spot. After the repair is completed, we will issue an official receipt with a warranty for up to 2 years.

Repair

To understand how a tachogenerator is repaired, you need to know what it is. The tachogenerator is a metal ring to which two wires are connected. It can be used to measure engine rotation speed. The measurement information is sent to the control module.

The tachogenerator is located on the rotating shaft. However, getting to it is not so easy. First you need to disassemble the Siemens or Bosch washing machine. How to do it?

Turn the device towards you with the back cover.
Remove the cover by first unscrewing the fasteners.
Find the engine. The metal ring, which is located on its shaft, will be the tachogenerator.

The malfunction of this part is determined by how the Bosch or Siemens washing machine operates.

From time to time the speed of rotation of the drum changes sharply.
During the spinning process, the drum rotates slower than expected.
When washing, the drum rotates much faster than it should.
The laundry is not completely wrung out.

To make sure that error F21 in a Bosch or Siemens washing machine indicates a malfunction of the tachogenerator, you need to conduct a test:

First remove the engine. To do this, you need to unscrew the bolts that hold it in place and disconnect all the wires.
Using a special device, measure the resistance on the wires that go to the faulty part. If everything is normal, it will be approximately 60 ohms.
Next you need to measure the voltage on the tachogenerator itself.
After taking all measurements, it is recommended to check how securely the part is fastened. If the fastening is loose, problems with the operation of the entire device may occur. As a result, error F21 will appear on the display or indicators.

Replacing the broken element will help eliminate the breakdown. This is very easy to do:

Separate the wires from the connectors.
Remove the part cover. It is usually secured with a latch.
Disconnect the fasteners that hold the tachogenerator.
Remove the faulty part and put a new one in its place.

Important Details

It is worth mentioning separately about the Bosch Maxx 5 and Bosch Maxx 7 devices. Error F21 in the Bosch Maxx 5 (Maxx 7) washing machine indicates problems with the engine. In most cases, they are caused by the brushes wearing out. The error can be eliminated by replacing the brushes. If your Bosch Maxx 5 or Bosch Maxx 7 machine still displays a fault code, it needs to be reset. Here's how to do it:

Close the door.
Set the switch to the “Off” designation.
Then turn it to the “Spin” program and wait until the code appears.
Press and hold the button that regulates the number of revolutions.
Turn the switch to “Drain”. Do not release the button for another 20 seconds.
Release the button and return the switch to its original position.
Repeat several times if necessary.

It is worth remembering that sometimes error F21 in Bosch Maxx 5 and Maxx 7 devices appears due to problems with the network voltage. You can eliminate it using a reset, as described above.

Error F21 in Bosch and Siemens washing machines means problems with the motor. They may be caused by malfunctions of certain parts, such as brushes or a tachogenerator. You can solve these problems yourself or by seeking help from a specialist.

Solution: algorithm for identifying the cause and troubleshooting

Often error F21 in Bosch washing machines occurs due to loading too much laundry. If removing part of it and restarting it did not help solve the problem, you can proceed to the next verification step.

After freeing the machine from the laundry, you need to pay attention to whether the drum rotates when scrolled by hand. If it does not spin during washing, but rotates manually, the belt is checked. If the drum does not rotate manually, you should check the machine part for foreign objects. They can get into the space between the tank and the drum.

If after checking the cause was not found, not only the Bosch washing machine is checked, error E21 could be caused by a sharp drop in voltage in the electrical network.

Next, if necessary, the body parts are checked: tachometer, motor, carbon brushes.