Theres a couple of things that can causes this fault. Theres the door lock and wiring to the lock, worn carbon brushes in the motor or the main control board.
The first thing to check is the door lock. Unplug the washer and open the door and remove the metal clamp around the door and unlip the door seal.
Then you can remove the door lock and pull it through the port hole.
Disconnect the wiring block and inspect the wiring block and see if theres signs of burning on there. If so then the lock will need to be replaced and the wiring blocked repaired. You can cut each wire out and retag the wires on there own.
If the door lock and wiring looks ok then you need a multi meter to test the lock. On there you will see 3 tags. Test beteen them all for contonuity and you should get a reading between 2 of them. If you dont then the lock is faulty and will need to be replaced.
But if the wiring and the door lock are fine then you need to remove the motor at the back at the bottom.
There at the back of the motor you will see the carbon brushes (if fitted as not all versions of this model use them)
If the carbon brushes are there remove them and see if they have worn. If so then you need to replace them.
But if the brushes are fine or your version hasnt got them then its going to be the main circuit board at fault here.
If you need anymore info just get back to me.
The clamp is in the groove on the outer edge of the seal.
The spring part of the clamp is normally in the 7 oclock position.
Theres eithere 2 screws holding the lock on or you will see 2 small pips. I will assume theres no screws there so look at the small pips on the door lock and push them both in and hold thet lock at the back and slid it backwards as you push thte pips in on the front and it will come out from there.
Thats it. If theres burning on there then thats the fault here.
You need to replace the door lock and retag the wires. To do this you get get new amp tags from the likes or B&Q and retag the wires so they are taged on there own and they will push onto the door lock.
But if you rather replace the wiring block with a brand new harness let me know and i can get the part number for you.
Ok if you not sure how to retag the wiring then i suggest replacing the lock wiring harness. As retagging you need to cut the wires and use amp tags to reconnect them. But if you get a new harness then it just pushes on and the other end goes to the control board so its a bit easyer to fit.
The part numbers for the lock is C00254755 and the wiring harness is C00268115.
As for getting the parts you can get them direct from Hotpoint. Click here for there website and just enter the part numbers in the search box and you will find them from there.
Just wondering how you got on with the washer as the question is still open. If you need anymore info just get back to me.
If not then if you could remember to rate the answer that would be great.