Door lock light flashes and leaks from manual outlet valve. Any ideas?

i got an Indesit WL103 2nd hand. Brother fitted it, tried it, all ok. I went out, came home and it was still on a cycle - 8 hours later so i turned it off. Have used the manual outlet valve to clear all the water but the door lock flashes and it wont do anything. Just tried it on a delay programme and the water started leaking out of the outlet valve even though it was done up!