Error F40 in the Bosch washing machine – how to fix

Bosch washing machine gave error F40? This means that there is a power problem.

Modern SMAs are equipped with an advanced self-diagnosis system. It immediately detects a failure at its first manifestation, notifies the user of this by showing an alphanumeric combination on the display. Your task is to notice, decipher and remove the error.

Today we will look at what code F 40 means and how to fix the malfunctions that caused it.

Decoding, signs and causes of error F40

The user manual lists all the fault codes for your Bosch washing machine model. But if the instruction is lost, we will tell you what error F40 means.

This is a power supply error.

The symptom of an error, as a rule, is one: the Bosch washing machine does not turn on and does not respond to button presses and program selection.

Main reasons

  • Low voltage in the mains. Below 190W.
  • Knocked out traffic jams or automatic.
  • The RCD worked.

Self-check: what to do

The cause of the breakdown in most cases is the power grid. Check the following points:

  1. Power off. As a rule, you will notice this, because the light will disappear in the entire apartment.
  2. Knocked out the machine. If water was poured into the outlet, a short circuit could occur, which is why the machine was knocked out. Carefully inspect the machine – it should be in the “ON” position.
  3. The RCD worked. If you installed an RCD, then it could work, turning off the flow of electricity. Often this happens due to leakage of electricity to the case and is accompanied by the fact that the Bosch washing machine is shocked. The RCD could simply “fail”, especially if you bought a Chinese-made device, or poor quality wiring was laid.
  4. Socket break. It may be that the contact in the socket itself is broken, so the CMA gives an F40 error. Check the outlet using another device. If the device is working, then the operation of the outlet is not broken. If there is no suitable electrical appliance at hand, take a tester or a 220V light bulb with wires connected. You can also check the phase with a special indicator screwdriver. If the outlet is working, and the SM shows an error, you need to look for other reasons to solve the problem.
  5. Often F40 lights up on the display if the power cord is faulty. Check the cable and replace if necessary. Testing is best done using a tester. It is not recommended to wrap the wire with electrical tape.
  6. Error codes appear due to a broken extension cord. Often, the SMA is connected to the network through a conventional surge protector – due to the fact that the outlet is far away or the power cord is short. Perhaps a filter failure is to blame for the fact that F40 is displayed on the screen. Check the extension cord and make sure that the machine is working from a regular outlet.

The washing machine does not turn on: additional reasons

If your washer does not start and the fault codes do not light up, other negative factors and breakdowns may be involved in this:

  • Breakdown of the “START” button. How to fix? Arm yourself with a tester and turn on the buzzer mode on it. Turn off the power to the machine and ring the power button in two states – “ON” and “OFF”. In the on position, the tester should beep – this means that the button is working. And in the “OFF” position, with a working button, the tester does not beep.
  • Breakage of the noise filter – FPS. The task of this filter is to dampen electromagnetic waves coming from the SM. This is necessary so as not to cause interference in other equipment that may be nearby. If the FPS fails, then it does not pass current, which prevents the washer from starting. To check the health of the filter, you need to remove the top panel of the machine. Ring the filter with a tester. If it is broken, you need to change the filter. Often FPS is sold immediately with a power cord. Important! Checking FPS requires experience. If in doubt, turn off the power to the machine, remove the wires and check the FPS with a tester by closing one probe at the input phase and the second at the output. FPS should ring. Do the same with “0”. If you find a breakdown, change the filter. 
  • Controller failure. If none of the above reasons suits you, there is only one thing left – a breakdown of the control unit. It is better not to do repairs on your own – this requires experience and skills, and do not forget that the board is quite expensive.

Often resetting errors does not require much effort. Therefore, if code F40 lights up in the Bosch washing machine, you know what to do.

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