What does error F21 (e21) mean on a Bosch washing machine, how to detect the problem and fix it?

The washing machine is loaded, the working cycle is started, but at some point the drum stops and the washing machine, by flashing indicators or the alphanumeric code e21 (f21), begins to signal a malfunction.

We’ll tell you in more detail what error code F21 means on a Bosch washing machine, where to look for the cause of the problem and how to fix 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 if there is a problem that the drum rotation is blocked by the blinking indicators:

1. The Bosch Classixx model signals error e21 by flashing the “Rinse” mode indicator (second light from the bottom).
2. 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).
3. 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.

Why does it appear and what to do?

Error e21 may provoke:

• foreign objects in the drum;
• low voltage in the power supply network at home;
• the drive belt slipped;
• engine malfunction;
• failure of the tachometer;
• control board failure.

Diagnosis of the cause of error E21 begins with the simplest possible faults, which will not be difficult to fix with your own hands.

Checking the drum

The first thing you need to do when error e21 occurs is to open the loading hatch door and turn the drum by hand.

To remove foreign objects, you must:

• turn off the washing machine;
• drain the remaining water through the drain filter;
• remove the powder receptacle;
• After unscrewing the fasteners, remove the control panel (there is no need to disconnect the wiring);
• Using a flat screwdriver, carefully pry off the thin metal clamp holding the rubber cuff of the hatch;
• tuck the cuff into the ram;
• Unscrew the fasteners and remove the front panel;
• disconnect the heating element wiring;
• push the central pin of the heating element inward, gently rocking it, and pull the heating element out of the body;
• remove foreign objects from the bottom of the tank;
• Reassemble the washer in reverse order.

Photographic recording of each stage of dismantling will help you assemble the washing machine in reverse order as quickly and without problems as possible.

Checking the network voltage

Engine failure can be caused by insufficient voltage in the electrical network at home.

You can determine whether this is so in the following way:

1. The power plug of the washing machine is pulled out of the socket.
2. Using a multimeter, check the voltage at the outlet.
3. Compare the obtained data with the parameters specified by the manufacturer in the passport of the household appliance.

If the network voltage does not meet the required parameters, installing a voltage stabilizer will help solve the problem. In the absence of experience and knowledge, it is better to entrust work with electricians to professionals.

Drive belt

One of the reasons for blocking drum rotation is a drive belt that has flown off the pulley.. It’s so easy to check: just remove the back panel of the washing machine and carefully return the fallen belt to its place.

Tacho sensor (Hall sensor)

The control module receives incorrect data about the engine rotation speed and, as a result, blocks the operating cycle, which the washing machine signals with error f21.

Test the operation of the tachometer (replace with a new one if necessary) can be done as follows:

1. After unscrewing the fasteners, remove the cover and rear panel of the washing machine body.
2. At the bottom of the case we find the engine, and on it there is a small metal ring with wires - a tachometer.
3. Disconnect the tachometer wiring from the engine.
4. Having set the multimeter to the “Resistance” mode, apply the probes to the contacts of the tachogenerator.

If the reading is 60 Ohm, the tachogenerator is considered to be in good condition, otherwise the sensor requires replacement.

Replacing a faulty tachometer is easy:

• remove the top cover of the sensor (use a thin screwdriver to pry up the special latches);
• unscrew the fasteners;
• dismantle the faulty sensor;
• installing a new tachogenerator;
• observing the connection diagram, we connect the tachometer wiring to the engine;
• We assemble the body of a Bosch washing machine.

In some cases, simply tightening the sensor fastenings (when the fastenings become loose, the tachogenerator begins to work intermittently) you can quickly eliminate error f21.

Engine

The drum rotates manually without problems, but when the washing process starts, the rotation of the drum is blocked - a characteristic sign that the cause of error E21 is a failed engine.

In order to test the motor of a Bosch washing machine, it is necessary to carry out a number of sequential actions:

1. After unscrewing the fasteners, remove the cover and back panel from the washing machine body.
2. Carefully rotate the pulley and remove the drive belt.
3. Disconnect the motor wiring.
4. Unscrew the mounting bolts and remove the motor from the washing machine body.

Additionally, check the motor for current leakage. To do this, one multimeter probe is applied to the motor housing, the second to the winding lamellas. The highest resistance value is a signal that the engine is working properly.

If everything is in order with the winding in the electric motor, the cause of error E21 most likely lies in worn carbon brushes. A dense layer of graphite dust on the motor housing of a Bosch washing machine is a sign that it’s time to change the brushes.

Algorithm of actions:

• disconnect the wire from the brush contact;
• pulling out the contact, remove the brush;
• clean the engine manifold with an abrasive sponge, then wipe with a soft cloth;
• We install new brushes - to do this, they are installed in brush holders and the contacts are connected.

It is necessary to ensure that the angle of the brush matches the radius of the commutator. After the winding has been tested and the carbon brushes have been replaced, the motor is installed in its original place, the washing machine body is assembled, and a test wash is started without load (at minimum speed, without laundry).

Control module

Sudden power surges or water getting inside the washing machine body can cause a malfunction of the control module. As a result, the feedback between the “brain” of the washing machine and the main elements of the internal device (motor, sensors, etc.) is disrupted.

Algorithm of actions:

1. Unscrew the fasteners and remove the cover from the washing machine body.
2. We take out the powder receptacle.
3. We unscrew the fasteners and dismantle the control panel.
4. We carefully inspect the control module.

Darkened tracks, scorch marks, faded, swollen varnish coating and bulges on the capacitor caps are signals that the control module requires repair. Lack of skills and knowledge of such work is a reason to turn to professional service center technicians for help.

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. All you have to do is leave a request by phone or on the website. 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.

How can I prevent future breakdowns?

Prevent problems that caused error e21 A few tips will help:

1. 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.
2. Small items of clothing, as well as underwear and socks are washed in special mesh bags.
3. 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.

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.

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.

Video on the topic of the article

Bosch will tell you about the F21 washing machine error in a video:

Conclusion

Eliminating error e21 is a step-by-step process, carried out according to the principle from simple to complex. Understanding the structure of the washing machine will help you quickly restore the functionality of the household appliance, otherwise you will have to seek help from a service center specialist.