How can I unlock my DEFY maximaid 800 front loader mid cycle? (no water in the drum yet) Thanks

The 'flat black round rubber' part is a non return valve so that water can't flow back washer to spinner, or spinner to washer. That part needs replacing. These machines are not available to us in North America, but this link should work well for you.

https://www.google.com/search?q=Defy+twin+tub+800+parts

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Page 19 of the manual says the code appears when the door is open. https://manualsbrain.com/en/manuals/797627/?page=19

That suggests to me to check the latch. https://www.youtube.com/watch?v=qokJ0DZfeTs

Most likely a bad switch.

Hello Elize!

I'm attaching here the Troubleshooting part of the manual to DEFY Maximaid 800. Hope it will help you! https://manualsbrain.com/en/manuals/797627/?page=19

Good day. I have got a defy front loader washing machine. It switches on, run in water but the drum doesn't turn?

It's the cable that goes to the heating element. It gets burnt/corroded. Rejoined mine and it's working perfectly now.

If you wish to get some details; check the site linked here. Pull up older posts....
http://electro-medical.blogspot.com/

according to that i think the problem come from timer after you fix this problem pleas donot select your program during conncting electrical power thankyou