Bosch Washer E27 Error Code - Causes & Fix

Bosch Washer E27 Error Code — What It Means

E27 on Bosch front-load washers is typically a door lock or interlock circuit fault. The machine cannot sense that the door has locked properly, or the lock assembly is failing to engage. This code is model-dependent and not consistently documented across all Bosch platforms, so always verify the definition in your appliance’s service literature using the E-Nr model number. On Bosch dishwashers, E27 means low mains voltage (below 170 V), but on washers the code points to the door lock system.

The washer will not start a cycle or will stop mid-cycle when E27 appears, because the control board requires confirmation that the door is securely locked before allowing water fill and drum rotation. Most cases trace back to a failed door lock assembly, damaged wiring at the lock, or a door that is not closing fully due to mechanical misalignment.

Jump to Fix

Common Causes

• Faulty door lock assembly The interlock switches or solenoid inside the lock fail and the control board cannot detect the locked state.
• Loose or damaged wiring at the door lock Harness connectors corrode, terminals break, or wires pinch where the door flexes, breaking the lock circuit.
• Door not fully closing The door striker is misaligned, the cabinet is out of square, or laundry is caught between the door seal and frame.
• Low or intermittent mains voltage If your washer shares the E27 voltage-fault behavior seen on Bosch dishwashers, household supply below 170 V can trigger the code.
• Control board or PCB fault When the lock and wiring both test good, a failed lock-circuit driver or relay on the main board can also cause E27.

Step-by-Step Fix

1. Verify your exact model E-Nr on the rating plate inside the door or on the frame, then check the service manual or Bosch parts diagram for that platform to confirm E27 refers to the door lock circuit.
2. Power off and unplug the washer, then wait two minutes for capacitors to discharge before opening any panels or touching electrical components.
3. Check the door mechanically by closing it slowly and watching the striker plate align with the lock tongue; remove any laundry or debris caught in the seal and confirm the door latches with a firm click.
4. Remove the top or front panel to access the door lock assembly, then disconnect the wiring harness and inspect the connector pins and wires for corrosion, heat damage, or breaks where the harness flexes.
5. Test the door lock assembly by consulting your model’s service data for the correct resistance or continuity values across the lock terminals; if the lock does not switch or shows an open circuit, replace the assembly.
6. If the lock tests good, check the control board side by measuring continuity from the lock connector back to the PCB and inspecting the board for burnt traces or failed relays in the lock circuit; replace the board only after confirming wiring is intact.
7. Reassemble the panels, restore power, and run a short test cycle to verify the door locks and unlocks correctly and the E27 code does not return.

Parts Often Needed

When to Call a Pro

Call a technician if you cannot locate your model’s service documentation to confirm the E27 definition, if you are not comfortable working with live mains wiring and electronic control boards, or if the fault returns after you have replaced the door lock assembly and verified all wiring. A qualified appliance technician has the correct service manuals, lock-circuit test procedures, and board-level diagnostic tools to isolate control-side faults safely. Also call for help if your household voltage is consistently low, since that requires an electrician to investigate the service panel and utility supply.