Siemens washing machine error E21

If your Siemens washing machine displays the E21 error code, it means the system has detected a problem with the motor or control board. In any case, restarting the machine and continuing the scheduled wash cycle will be impossible; you'll need to troubleshoot the issue first. Let's take a closer look at what to do and how to avoid making the situation worse.

Problems to be encountered

The beauty of a self-diagnostic system is that it makes it much easier to determine the location of a breakdown. So, if the machine displays error E21, it means the washing machine is unable to spin the drum – the Siemens motor has failed. The reason may be:

• faulty Hall sensor;
• worn out carbon brushes;
• problems with the motor lamellas or windings;
• control board failure (the triac has burned out or the relay has been damaged).

Any of the above malfunctions will prevent the washing machine from starting. As a result, the drum remains motionless, the system detects a lack of response to the command, terminates the cycle, and displays the E21 error code. But don't be alarmed by this combination—most problems can be easily fixed at home. Here's what to do if the E21 error appears:

• de-energize Siemens and turn off the water supply;
• unscrew the two screws from the back wall and remove the top cover;
• detach the back panel from the case;
• pull the drive belt off the pulley;
• place the machine gun on its left side;
• find the motor located under the tank on the right;
• disconnect the power supply;
• loosen the engine holding fasteners;
• Pull the engine towards you and remove it from the “socket”.

Troubleshooting the E21 error on a Siemens washing machine requires a sequential diagnosis of all motor components, from the tachometer to the control board. The first step is to inspect the tachogenerator. It should monitor the motor's RPM, but if it malfunctions, it stops transmitting information to the module, which then responds by terminating the cycle. The tachogenerator is tested using a multimeter:

• turn on the ohmmeter mode;
• we touch the sensor contacts with the probes;
• look at the display (the recorded resistance should not be large).

Next, we manually inspect the brushes, which are attached to both sides of the motor. Loosen the screws holding them in place, disconnect the wires, move the contacts, and remove the carbon tips from the housing. Measure the freed carbon tips with a ruler—if their length is less than 0.7-1 cm, they need to be replaced.

Are the slats intact?

The next step in the repair is checking the integrity of the fins. These are the metal plates that conduct current between the motor components. If they become detached or blown off, the voltage is not transmitted, and the motor stops. To check the fins, remove the rotor from the motor and carefully inspect its surface. Minor detachments of up to 0.5 cm can be repaired with sandpaper or a grinder. Otherwise, the motor must be replaced.

When diagnosing the slats, we also "clean" the Siemens washing machine motor. We dust off the dust, clean the grooves, and polish the housing. It's also recommended to wipe down the motor:

• return the engine to the "nest";
• connect the wiring;
• do not tighten the belt;
• run the spin cycle twice at minimum speed;
• put on the belt and run the wash for an hour.

Afterwards, it's recommended to wash 2-3 cycles on a gentle cycle. Load the drum halfway and use a program with minimal spin.

"Resetting" the error

After troubleshooting your Siemens washing machine, you need to reset the error code. The "zeroing" algorithm E21 may vary depending on the machine model. As a rule, you should:

• turn the programmer to "0";
• rotate the selector one notch counterclockwise;
• press and hold “Start” for 2-3 seconds (on some models – “Spin”);
• return the programmer to "0".

After a while, Siemens will respond to the reset, the error will disappear from the display, and the system will be ready for another wash. Sometimes, resetting E21 doesn't work on the first try; you'll have to try again 2-3 times.

   

2 reader comments

1. November 24, 2021 at 4:33 PM

   Anonymous:

   Thanks for your help!

   Answer
2. January 5, 2022 at 9:01 PM

   Denis:

   Hello! Please help me resolve error F:67 on my Siemens WM16S75 iQ700. It popped up when I turned it on, and disconnecting it from the power source didn't clear it. Thanks in advance!

   Answer