Contents
Your Bosch washing machine shows error F20 on the display. What the fault code means can be found by indirect signs of a problem. You notice that things shed and shrink after washing, and the walls of the washer are too hot. This indicates that the water is heating up too much, the temperature does not match the selected program.
Models without a screen signal an error by flashing (glow) the RPM lights: 800-1000, 800-600.
Note! Error F20 is critical and can cause a short circuit. Therefore, do not start the Bosch machine before correcting the situation.
Let’s figure out together what to do in this case.
Self troubleshooting
Now you understand what error F 20 means: unplanned water heating occurs. At the same time, Bosch SM can stop in the middle of washing, the buttons on the panel do not respond to pressing.
The reason that the system generates an F20 error can be either a minor malfunction or a breakdown that requires repair. Do the following first:
- Unplug your Bosch washing machine. If the error code is displayed at the end of the program, unplug the power plug and remove the laundry.
- If during operation you find steam and heat coming from the hatch, stop the program. Try to automatically drain the water. If it does not come out, then wait until the water cools down (at least a few hours) and drain it through the filter.
After unloading, try to reboot the system. Unplug the Bosch machine for 20 minutes, then turn it on. Error F20 has been reset – the problem is localized.
How to troubleshoot when the error code is on the display again? We will analyze the main problems and ways to solve the problem.
How to repair and troubleshoot
Checking the elements of the washing machine will help restore the Bosch SMA and remove the F20 error.
Heating element relay
This breakdown is typical for Bosch electronically controlled washing machines. The thermistor (thermostat), which detects the temperature of the water, signals the control board to turn off the electric heater. The heating element relay receives a signal, giving a command to turn off.
In case of “sticking” (malfunction) of the relay, the heating element does not stop heating. As a result, it may burn out, and the part will need to be replaced. But first of all, check the relay, if necessary, install a new element.
temperature sensor
Thermistor (thermostat) measures the temperature of water heating. It can fail due to the formation of scale, which prevents the device from working normally. Or due to combustion. To check both options, you need to get to the sensor:
- Remove the front panel of the Bosch washing machine. This video shows in detail how to remove the front panel:
- The sensor is located inside the electric heater, which is located at the bottom of the machine.
- Disconnect the heater connectors and the thermistor harness by pressing the release tab.
- Loosen the center nut with a wrench.
- Pull out the temperature sensor.
- Installing a new part is carried out in the reverse order. Video will help:
Electronic module or programmer
Since the module does not give a signal to turn off the heating element, overheating can occur by 10°, 20° and even 30°C. Therefore, you need to check the control board, ring all the elements and connectors with a multimeter.
Do not forget to inspect the wiring between the module and the heating element. It is possible that the signal is not transmitted due to a broken wire.
If it is within your power, repair the module. If the element is completely defective, it must be replaced.