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Error code reference

Bosch Cooktop Error Code ER 22

Keyboard error detected by the mTwist control system.

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Keyboard error detected by the mTwist control system.

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What ER 22 means on a Bosch cooktop

ER 22 on a Bosch cooktop indicates a keyboard error detected by the mTwist control system. The mTwist system is the integrated touch and rotary control architecture used in certain Bosch induction and electric cooktops, combining a microprocessor-based control board with a capacitive touch keypad interface. When the control system detects an anomaly in the keyboard input signals, such as a stuck key, unresponsive touch zone, or a breakdown in communication between the keypad assembly and the main control board, it triggers the ER 22 fault to halt operation and protect the unit.

The keyboard in this context refers to the touch control panel, which uses capacitive sensing to register user input. Common triggers include physical contamination on the glass surface causing a false continuous key press, a failed or shorted touch sensor element, damage to the ribbon cable connecting the keypad to the control board, or a failure within the control board itself that misinterprets keypad signals. Moisture intrusion from spills is a particularly frequent contributor, as liquids can bridge touch zones and simulate a stuck key condition.

Because the mTwist control system continuously monitors keypad input for validity, even a brief or intermittent fault in the keyboard circuit can latch the ER 22 code. Technicians should inspect the cooktop surface for residue or moisture, examine the ribbon cable connections for corrosion or physical damage, and evaluate the control board if surface-level causes are ruled out. Component replacement at the keypad or board level may be necessary if the fault persists after cleaning and inspection.

Source: manufacturer service documentation.

Common causes of ER 22

  1. 01

    Moisture or residue on the touch surface

    Wiring / connection

    Liquid spills or grease buildup on the glass control surface can bridge capacitive touch zones and simulate a continuously pressed key, triggering ER 22. Thoroughly cleaning and drying the surface is the first step.

  2. 02

    Stuck or shorted touch key

    Part replacement

    A physically damaged or failed touch sensor element within the keypad can send a constant or invalid signal to the mTwist control system. Inspect the panel surface for visible cracks or deformities near control zones.

  3. 03

    Damaged or disconnected ribbon cable

    Part replacement

    The ribbon cable connecting the touch keypad assembly to the main control board can develop corrosion, kinks, or loose connections, interrupting the keyboard signal. Visual inspection of the cable and its connectors is required.

  4. 04

    Failed touch keypad assembly

    Part replacement

    The capacitive keypad assembly itself can fail internally due to age, heat exposure, or moisture intrusion, producing erratic or absent input signals. Replacement of the keypad assembly is typically required if this is confirmed.

  5. 05

    Faulty main control board

    Part replacement

    If the mTwist control board has developed an internal fault, it may misinterpret or fail to process keypad signals correctly, generating ER 22 even when the keypad itself is functional. This is typically diagnosed after ruling out all other causes.

See the test procedure for each cause

Frequently asked questions about ER 22

What does ER 22 mean on a Bosch cooktop?
ER 22 indicates a keyboard error detected by the mTwist control system, which manages the touch control interface on your Bosch cooktop. The system has identified a problem with the keypad input, such as a stuck key, a failed touch sensor, or a communication fault between the keypad and the control board. The cooktop stops normal operation when this code appears to prevent unintended activation of the heating elements.
Can I fix ER 22 on my Bosch cooktop myself?
In some cases, yes. Start by turning off the cooktop, wiping the entire control surface clean with a dry cloth to remove any moisture or residue, and then restoring power. If the error persists, further diagnosis involves inspecting the ribbon cable and keypad assembly, which requires accessing the interior of the unit and is better suited for technicians with appliance repair experience. Internal component replacement, such as the keypad or control board, is generally not a simple DIY repair.
Will resetting the cooktop clear the ER 22 error?
A power reset by switching off the circuit breaker for 30 to 60 seconds may temporarily clear the ER 22 code if the fault was caused by a transient issue like a momentary moisture contact. However, if the underlying cause, such as a failed touch sensor, damaged ribbon cable, or faulty control board, has not been resolved, the error will return. A reset alone is not a fix, just a diagnostic step.
Is it safe to use my Bosch cooktop while ER 22 is displayed?
No. The ER 22 code indicates the control system cannot reliably read keyboard input, which means the cooktop cannot safely process user commands. Operating the unit in this state could lead to unintended heating behavior. The cooktop should remain off until the fault is diagnosed and repaired.
How much does it cost to repair an ER 22 error on a Bosch cooktop?
Repair costs depend on the root cause. If cleaning resolves the issue, the cost is minimal. Ribbon cable replacement or keypad assembly replacement typically falls in the range of $80 to $250 in parts, plus labor if a technician is involved. Control board replacement is generally the most expensive repair, with parts and labor potentially ranging from $200 to $500 or more depending on the specific model.

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