E40
Bosch Washing Machine
Severity: MinorWhat Does This Error Mean?
The E40 error means your Bosch washer has detected a problem with the door lock mechanism. The machine cannot confirm that the door is securely latched before starting or continuing a cycle. This is a safety feature — running a front-load washer with an unsecured door could cause the door to open during the cycle, flooding your floor. In most cases this is a simple fix, though a worn door lock assembly sometimes needs replacing.
Affected Models
- Bosch 300 Series
- Bosch 500 Series
- Bosch 800 Series
- Bosch WAT28400UC
- Bosch WFMC2201UC
- Most Bosch front-load washing machines
Common Causes
- The door was not pushed firmly closed before the cycle started
- Clothing is caught in the door seal, preventing the door from latching fully
- The door latch hook or striker is worn and no longer engages the lock mechanism reliably
- The door lock module (electronic interlock) has failed and cannot signal 'locked' to the control board
- A damaged door hinge has caused the door to sit slightly out of alignment with the lock receiver
How to Fix It
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Push the door firmly closed until you hear and feel the latch click.
Bosch front-load doors need a firm, deliberate push to engage the lock. A gentle close is often not enough.
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Open the door and inspect the rubber door seal. Run your hand around the entire inside of the seal, feeling for any clothing, small items, or debris caught in the fold.
Socks, underwear, and small items frequently get trapped in the door seal fold and prevent the door from seating fully.
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Look at the door latch (the plastic hook on the door) and the lock receiver (the slot on the machine body). Check both for visible wear, cracking, or damage.
On older machines the latch hook can wear down over years of use and no longer engage deeply enough to trigger the lock.
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Unplug the washer for 60 seconds, then plug it back in. Close the door and try starting a cycle.
A power reset clears control board memory of the fault. If the lock is mechanically fine, this may resolve E40.
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If E40 persists with the door clearly latched, the door lock module has likely failed electronically. Call a Bosch-authorized technician for replacement.
The door lock module is a small electronic component inside the machine at the door latch area. A technician can test it with a multimeter and replace it if it has no continuity.
When to Call a Professional
If cleaning the seal and closing the door firmly does not clear E40, the door lock module likely needs replacing. Door lock module replacement costs $100 to $200 including parts and labor. Hinge adjustment or replacement runs $80 to $180. Contact Bosch service at 1-800-944-2904 to check warranty coverage.
Frequently Asked Questions
Is it dangerous to use the washer with E40?
The machine will not run while E40 is active — it locks itself out as a safety measure. You cannot accidentally start a cycle with an unsecured door. There is no immediate danger from the error itself. However, do not try to force or bypass the door lock — this defeats the safety system and could be dangerous if the machine ever did start with an unsecured door.
How do I open the door if E40 triggered mid-cycle?
If the machine stopped mid-cycle with water in the drum, do not force the door open. First, try running a drain cycle — select Spin or Drain and press Start. Once the drum is drained, the door lock should release automatically after about 2 minutes. If the door still will not open, unplug the machine and wait 5 minutes — the lock spring should release. As a last resort, there is usually an emergency door release cord behind the kick plate at the bottom front of the machine.
How long does a Bosch washer door lock last?
Bosch door lock modules are built to last the life of the machine — typically 10 to 15 years. However, the mechanical latch and hook can wear faster with heavy use. Slamming the door rather than pushing it firmly is the fastest way to damage the latch. Close the door with steady pressure, not impact, to extend the lock's life.