The E42 error on your Bosch Dishwasher means the control panel has detected a fault with the door latch or key panel lock function. In most cases the dishwasher will pause the cycle and refuse to start until this is resolved.
| Error code | E42 |
|---|---|
| Meaning | Door lock or key panel lock circuit fault detected by the control board |
| Severity | Medium — the dishwasher won't run a cycle until fixed, but it's rarely a safety issue |
| Time to fix | 10–40 minutes |
| Tools needed | Screwdriver, multimeter (optional, for advanced checks) |
What the E42 error means
E42 is triggered when the dishwasher's electronic control board senses that the door isn't latching correctly, or that the button lock feature has been engaged unintentionally. The machine uses this code as a safety measure to stop water and heating cycles from running with an unsecured door. It's similar in concept to other Bosch appliance fault codes that flag mechanical or electrical mismatches, the kind of issue you'll also see explained in guides like Bosch Drill Won'T Start: Causes and How to Fix It, where a safety interlock stops the tool from operating until conditions are correct.
Common causes
- Door not closed fully or latch misaligned
- Key/button lock accidentally activated on the control panel
- Worn or damaged door latch assembly
- Moisture or condensation affecting the control panel sensors
- Loose wiring connector between the door switch and control board
- Faulty main control board (less common)
How to fix the E42 error
- Close and reopen the door firmly — Make sure the door is pushed shut until you hear or feel it latch, then restart the cycle.
- Check for the key lock symbol — Look at the display for a lock icon; if present, press and hold the lock button (usually 3 seconds) to disable it.
- Power cycle the dishwasher — Turn off power at the breaker for 2–3 minutes, then restore power and try starting a cycle again.
- Inspect the door latch — Open the door and check the latch mechanism for cracks, looseness, or debris; clean and realign if needed.
- Dry the control panel — Wipe down the panel and surrounding area if there's visible moisture, then let it air dry for 10 minutes before retesting.
- Call a qualified appliance technician — If the error persists after these steps, the control board or door switch may need replacing.
FAQ
Can I still run a cycle with the E42 error showing?
No. The dishwasher blocks cycle operation until the door lock fault clears, so the code needs to be resolved first.
Does E42 mean the dishwasher is broken permanently?
Not usually. Most cases are caused by a door not latching properly or the key lock being engaged, both of which are quick fixes.
How do I know if it's a wiring issue rather than a simple door problem?
If the error keeps returning after confirming the door latches correctly and the key lock is off, it's likely a wiring or control board issue that needs a technician's multimeter check.
