What Does Error Code E42 Mean on a Siemens Washing Machine?
Unplug the machine from the mains, wait 2 minutes, then plug it back in and press the door release — this resets the door lock solenoid and clears a temporary electronic latch fault in the majority of cases (takes about 5 minutes).
Fault description
Error code E42 means your Siemens washing machine has detected a problem releasing the door lock at the end of a cycle. The machine's control system expects the door interlock to disengage within a set time window; when that doesn't happen, E42 is logged and the cycle is halted to prevent you forcing the door open and causing damage.
In practical terms, you'll typically see the error displayed on the panel after a wash or spin cycle completes, with the door remaining firmly locked and unresponsive to the release button. The drum may have stopped, but the door interlock solenoid has either failed to retract or has not received the correct signal from the control board to do so.
The fault affects the door locking system — a small but critical assembly that keeps the door sealed during operation and releases it safely once conditions are met. Both mechanical and electronic faults can trigger E42.
Causes
- Faulty door lock mechanism (interlock) — The door interlock contains a solenoid and a bi-metallic strip that physically releases the latch. If either component fails or wears out, the lock cannot disengage even when the control board sends the correct signal.
- Jammed or obstructed door latch — Small items of clothing, debris, or a warped door seal can physically obstruct the latch tongue or the catch on the door frame. This prevents the mechanism from moving freely, even if the electrical side is working correctly.
- Residual drum pressure or water in the drum — If the drum has not fully drained or depressurised, some machines will keep the door locked as a safety measure. A partial drain fault can therefore present as E42 even though the lock itself is fine.
- Wiring fault between the door lock and control board — The wiring harness connecting the interlock to the main PCB can develop a loose connector, a broken wire, or corrosion over time. This interrupts the signal that tells the board the door has unlocked.
- Control board (PCB) fault — If the main control board fails to send the unlock signal at the correct point in the cycle, the door will remain locked regardless of the condition of the interlock itself. This is less common but possible, particularly on older machines.
Step-by-Step Fix
- 1
Power cycle the machine
Switch the machine off at the programme dial, then unplug it from the mains socket. Wait at least 2 minutes to allow the door lock solenoid to cool and reset, then plug back in and try the door. This resolves temporary electronic glitches and is always the right first step.
- 2
Check for water remaining in the drum
Look through the door glass — if you can see standing water, the machine may be keeping the door locked for safety. Run a Drain or Spin programme to clear the water. Once the drum is empty and the cycle ends normally, the door should release.
- 3
Use the emergency door release cord
Most Siemens washing machines have a manual release cord located behind the filter access panel at the bottom front of the machine. Open the panel, locate the small coloured tab or cord, and pull it firmly downward. This mechanically disengages the lock and allows you to open the door safely.
- 4
Inspect the door latch and catch for obstructions
With the door open, examine the plastic latch tongue on the door and the metal or plastic catch on the machine body. Look for trapped fabric, debris, or visible damage. Clean away any obstruction with a damp cloth and check that the latch moves freely by pressing it with your finger.
- 5
Check the door seal around the latch area
A swollen or misaligned door seal (gasket) can press against the latch and prevent it from releasing cleanly. Run your fingers around the seal near the latch point and look for tears, bulging, or areas where the seal has rolled out of its retaining groove. Reseat the seal if it has come loose.
- 6
Inspect the door lock wiring connector
If you are comfortable working with the machine unplugged, remove the top panel (usually two screws at the rear) and locate the wiring connector on the back of the door interlock. Unplug it, check for corrosion or bent pins, and firmly reseat it. A loose connector here is a common cause of intermittent E42 faults.
- 7
Test or replace the door interlock assembly
If all the above steps fail, the interlock itself is the most likely culprit. Door interlocks are a standard spare part for most Siemens models and can be replaced with basic tools. With the machine unplugged, remove the door seal retaining band, pull back the seal, and unscrew the interlock from the front panel. Fit the new part and reassemble in reverse order.
Affected models
Select your model to see its full troubleshooting page.
When to call a service technician
If you have replaced the door interlock and the E42 error returns immediately, or if the door lock wiring appears burned, melted, or severely corroded, stop and contact a service technician. These symptoms suggest the fault lies with the main control board or a deeper wiring issue that requires diagnostic equipment to trace safely.
You should also call a service technician if the drum is completely inaccessible — for example, if the emergency release cord is broken or missing and you cannot open the door by any of the methods above. Forcing the door risks cracking the door glass or breaking the hinge, turning a simple repair into a much more expensive one.
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Frequently Asked Questions
Is it safe to leave the machine with the door locked after an E42 error?
Yes, it is safe to leave it for a short time — the machine will not operate with the door locked and the error displayed. However, if there is wet laundry inside, try to open the door within a few hours using the emergency release cord to prevent mildew forming on the clothes and inside the drum.
Can E42 appear even if the door lock is brand new?
Yes. If the fault lies with the control board or the wiring harness rather than the interlock itself, a new lock will not resolve the error. If E42 returns shortly after fitting a replacement interlock, the next step is to check the wiring connector and, if that is sound, have the PCB assessed by a service technician.
How do I open the door manually on a Siemens washing machine?
Open the small access panel at the bottom front of the machine — it usually clips or screws off. Inside, near the drain filter, you should find a small coloured tab or cord. Pull it downward firmly and hold it while you pull the door open. Always make sure the machine is unplugged before doing this.
How much does a Siemens door interlock cost to replace?
Door interlock assemblies for Siemens washing machines typically cost between £15 and £40 for the part, depending on the model. If you fit it yourself the total cost is just the part price. A service technician call-out will add labour costs on top, but the overall repair is still usually economical compared to replacing the machine.
Will E42 clear itself after a power cycle, or does the fault need to be reset manually?
In many cases, a full power cycle — unplugging for 2 minutes — is enough to clear a temporary E42 and allow the door to release normally. If the underlying cause is a worn interlock or a wiring fault, the error will return on the next cycle or the one after. A fault that keeps coming back needs a physical repair, not just a reset.