Error F21 in a Siemens washing machine

Regardless of the model and configuration, error F21 in a Siemens washing machine indicates one thing - a serious breakdown has occurred. It will not be possible to start the machine and continue washing: first you need to eliminate the malfunction and reset the signal code. You will have to pay attention to the washing machine motor and control system. We will tell you how to restore the functionality of your “home assistant” without aggravating the problem using step-by-step instructions and explanations.

What failures does the code cause?

The main merit of Siemens machine fault codes is that they allow you to narrow down the search for a breakdown. So, the illuminated inscription from F21 indicates a forced stop of the drum. To correct the situation, we first correctly diagnose the source of the problem. They may be:

• broken tachogenerator;
• worn electric brushes;
• burnt triacs;
• damaged reverse relay.

The mentioned malfunctions prevent the full functioning of the control system and the operation of the motor. The drum stops rotating and the machine cancels the set cycle. Despite the seriousness of the breakdown, you can determine the causes and carry out repair work yourself. Step-by-step instructions on what to do when error F21 appears looks like this.

1. Disconnect the washing machine from communications.
2. Unscrew the two screws at the back and slide the top cover.
3. Remove the back wall.
4. Remove the drive belt.
5. Turn the machine over to its left side.
6. Loosen the screws holding the motor.
7. We disconnect the supply wires, the chip and the ground.
8. We sharply pull the engine towards ourselves.

Having placed the engine on a flat surface, we begin to sequentially check it for existing faults.First of all, let's inspect the tachometer generator. On Siemens machines, this sensor breaks down extremely rarely, so its failure is unlikely.

We test with a multimeter, connect the probes to the contacts and evaluate the result: the final voltage should not be high.

Next, we turn our attention to electric brushes. They are located on both sides of the engine and are removed from the housing after unscrewing the retaining bolts. We take them out of the holders by pulling out the brass bar and carefully disconnecting the contacts, and measure the carbon tip. If the length is less than 0.7-1 cm, we replace both brushes with new ones.

Checking the engine correctly

Do-it-yourself repairs continue with a more complex procedure - checking the engine for the integrity of the lamellas. To do this, completely remove the rotor from the motor and inspect the collector. If peeling or blowing is noticeable, it is necessary to replace the engine or rotor (if peeling is up to 0.5 mm, you can temporarily sharpen the surface).

Be sure to clean the engine housing from any existing dust and contaminants. We pay special attention to the grooves between the lamellas and polish the entire surface. You should not neglect grinding in, which is carried out like this:

• install the motor back;
• connect the wires (do not put on the drive belt);
• run the spin cycle twice at minimum speed;
• return the belt to its place;
• We turn on a mode lasting at least an hour with an empty drum and minimal spin.

Afterwards we take precautions. For the first 2-3 cycles, load the drum halfway and select low powers. Next, we use the machine in the usual way.

After renovation

To continue washing, in Siemens machines it is necessary not only to fix the breakdown, but also to reset the signal code.The error cancellation algorithm for different models may differ, but not critically. Most often, it is enough to take the following steps:

• turn the program selector to position “0”;
• move one space to the left;
• press “Start” and hold for 2-3 seconds;
• return the cursor to its previous position.

You just have to wait a little, after which the code will be reset and the machine will be ready to start. Often the procedure has to be repeated several times. Sometimes instead of “Start” you have to try the “Spin” button.

2 reader comments

1. 06/15/2020 at 14:15

   Technician:

   Very pleased with those. support, sensibly written.

   Answer
2. 04.12.2021 at 19:39

   Andrey:

   Cannot be erased, error f21 on SIEMENS ADVANTIQ IQ300. Touch buttons do not respond.

   Answer