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Error code reference

Bosch Washer Error Code Er:24

Motor power relay failed

Bosch codesBosch washer codes

Motor power relay failed — faulty control module.

First step from the service manual

Replace faulty control module.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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  • Wiring diagram references and connector pinouts from the OEM service manual
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What Er:24 means on a Bosch washer

Er:24 on a Bosch washer indicates that the motor power relay on the main control module has failed. The motor power relay is an electromechanical switch integrated into the control board that opens and closes the circuit supplying power to the drive motor. When the control system detects that this relay is not operating correctly, either failing to close and engage the motor or failing to open and cut power as commanded, it logs Er:24 and halts the wash cycle to prevent potential damage to motor components or other downstream circuitry.

The root cause of Er:24 is a faulty control module. Relay contacts inside the board can burn, pit, or weld together over time due to repeated high-current switching, particularly during motor start cycles when inrush current is at its peak. A welded relay contact is especially hazardous because it means the motor circuit cannot be fully de-energized by the control system. In some cases, the relay driver circuit on the board itself fails rather than the mechanical relay contacts, producing the same fault condition.

Because the relay is soldered directly onto the control board rather than being a standalone serviceable component in most Bosch configurations, the standard repair path is full control module replacement. Attempting to operate the washer with an active Er:24 fault is not recommended, as an uncontrolled motor relay state can lead to unpredictable motor behavior or electrical hazards.

Source: manufacturer service documentation.

Common causes of Er:24

  1. 01

    Failed motor power relay on control board

    Part replacement

    The relay contacts on the control board can burn or weld shut after repeated high-current motor start cycles. This is the primary cause of Er:24 and requires control module replacement.

  2. 02

    Relay driver circuit failure on control board

    Part replacement

    The transistor or driver component that signals the relay to open or close can fail independently of the relay contacts themselves, producing the same Er:24 fault. This also requires replacing the control module.

  3. 03

    Control board damage from power surge

    Part replacement

    A voltage spike or power surge can damage the relay circuit on the control board. Check for any history of power outages or tripped breakers around the time the error first appeared.

  4. 04

    Intermittent wiring connection to control board

    Wiring / connection

    Loose or corroded connector pins at the control board harness can cause the relay circuit to misread its state. Inspect all connectors to and from the control board before ordering a replacement board.

See the test procedure for each cause

Frequently asked questions about Er:24

What does Er:24 mean on a Bosch washer?
Er:24 means the motor power relay on the main control module has failed. The relay is the internal switch the board uses to send power to the drive motor. When it malfunctions, the washer stops the cycle and displays this code to prevent further damage. The control module must be replaced to resolve the fault.
Can I fix Er:24 myself, or do I need a technician?
Replacing a control module requires disconnecting the washer from power, accessing the control board housing, and carefully transferring wiring harness connectors to the new board. Knowledgeable DIYers comfortable working with appliance electronics can perform this repair. However, because a failed motor relay can involve a welded contact that leaves the motor circuit live, it is safest to have a qualified technician handle the diagnosis and replacement.
Is it safe to keep using my Bosch washer with Er:24 showing?
No, you should not continue operating the washer with Er:24 active. A failed motor power relay can mean the motor circuit is not properly controlled, which creates a risk of unpredictable motor operation or an electrical hazard. Stop using the machine and have the control module inspected and replaced before running another cycle.
How much does it cost to fix Er:24 on a Bosch washer?
Control module replacement is the required repair for Er:24. Parts costs for Bosch washer control boards typically range from $150 to $350 depending on the model. Adding professional labor, total repair costs generally fall between $250 and $500. Getting a firm quote from a technician before proceeding is recommended, since costs vary by region and model.
Will resetting my Bosch washer clear the Er:24 error code?
A power reset may temporarily clear the code from the display, but it will not fix the underlying relay failure in the control module. Er:24 will return as soon as the washer attempts to start the motor again. A reset should only be used as a brief diagnostic step to confirm the fault is repeatable, not as a substitute for replacing the faulty control module.

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