VERIFIED
The forgotten mug
Everyone has done it. The dishwasher is running, you spot a cup on the counter, and you pull the door open to slip it in. Steam pours out, you close the door, and a few seconds later the display shows E21. Was that an error or just the machine objecting to being interrupted?
How to tell
Bertazzoni does not publish a single meaning for E21 that holds across all dishwashers, so the safest assumption is that the control noticed something unexpected. A door switch tells the control the door is closed and the latch holds it shut during the cycle, so opening it mid-cycle removes the signal the control expects. A mid-cycle interruption is an unexpected event by design. Run a full cycle without touching the door. If E21 does not return, the interruption was the cause and nothing is wrong.
If it returns on an untouched cycle
That moves the story along. The signal the control gets from the door, or from a sensor near it, may be unreliable, and the machine is not just reacting to your hand. A repeat of the code at random points of a cycle is typical of this kind of intermittent trouble.
Safe checks
- Press the door closed with the flat of your hand and check that it seats evenly all around.
- Wipe the gasket and the front edge of the tub for dried detergent.
- Make sure the racks slide fully in and that nothing sticks out from the sides.
- Listen for a faint click at the latch when you close the door.
Opening the door while it runs
A word of care here. Opening a hot cycle releases scalding steam, and hot water may be inside the tub. Pause the cycle first and wait a moment, rather than yanking the door open. Repeated interruptions also stress the latch.
Why the visit is needed
An intermittent door or leak-type signal can only be understood with the machine open and powered, which is why the repeat case is a technician job. The technician tests the door switch, the wiring through the hinge area and the board input. The door gasket seals water in rather than sensing anything, so a worn gasket and a switch fault show different signs, with leaks pointing toward the gasket. Expect a written estimate after diagnosis, and nothing is replaced without your approval.
Tell the technician how many times the code has happened and whether any of those were after the door was opened.
Notes for the booking
Count how many times E21 has appeared and which of those followed a door opening. If the tub was hot and you opened it, say that too. A clear history of one or two interruptions is reassuring, while a code on an undisturbed cycle is the thing a technician needs to hear about.
Frequently asked questions
It is not harmful if you pause first, but hot steam and water can escape. Avoid doing it often.
If it was caused by the interruption, yes. If it comes back on its own, book a visit.
Maybe, but the code has no confirmed single meaning, so testing is needed.
Model compatibility: Bertazzoni reuses codes across series and model years, so E21 may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.
