My Hotpoint bs1400 extendia washing machine made in 2005 is stuck in test mode. When test mode has run it displays end. If you then open the door and close it it shows normal program, mode but when you hit start it goes straight to end. If you switch of mains it comes back in in test mode.

SOURCE: wf860p computer control automatic

I have had this problem it is caused by accidentally pressing both the on and start button together. It puts the machine into demo mode. You need to press both the buttons together again for about 30 seconds. If it doesn't work first time switch the machine off and do it again. Sometimes you have to do this many times before it works but eventually it does work.
Very frustrating.
I found the cause was either leaning on the front of the machine or resting a broom which when you pick it up accidentally presses the two buttons.

SOURCE: HOW CAN I GET MY HOTPOINT AQUARIUS 1400 - OFF CONSTANT TEST PROGRAM?

This works

To exit the TEST mode, press and hold down the "Start/Cancel" button until ALL of the console lights light up. Press both "Start/Cancel" and On/Off buttons simultaneously until " dOFF " appears in the display. The default setting will now appear and the machine can be used normally.

SOURCE: my hotpoint ultima super silent displays 'test' but dnt run cycle

its in factory test mode, this can be set by pressing the on and start buttons together. to reset, turn on while pressing the on and start together until dOFF appears

SOURCE: My Hotpoint Aqualtis washing machine

My Aqualtis just stopped mid program with F-05 on the display. This is apparently a failure to drain properly. I was luckily able to hold the power button to cancel the current program drain the water out (very slowly) and empty the machine.
THIS IS HOW I RESOLVED MY PROBLEM.
Disconnect the machine from the mains. Turn off the water supply to the machine. Disconnect the cold water pipe from the machine at the top corner.(Watch out for some water) Remove the drain hose from where you have it going to.  Pull the machine out and lay it gently down on the left side panel (use a towel to protect the side and absorb any water). Then, from the now exposed underside there is a black rubber pipe connected to the pump (black) coming from the main drum. Use some pliers to pinch the steel spring that clamps the hose in place and remove. Then using your fingers (there is nothing sharp in there) see if you can find any blockage.
I REMOVED: A pound coin, a dairylea slice wrapper and a piece of kinder bueno packet.
Carefully replace the black hose making sure it is fully on. Replace the drain hose, reconnect the water pipe and turn the water back on. (check to see it's dry with no leaks). Plug it in, turn on and that for me was it. Job Done.

SOURCE: washing machine stuck in test mode hotpoint wf865

To get out of it you need to press start, the display should go daft. Press start again and the display should settle down. Now press the on/off button and the start button at the same time and hold them down for a few seconds until the display shows d-end or d-off.
Your machine should now work. hope this helps.