please help! big leak from water tank last pm

Hi,
im a girl and no nothing about plumbing but will try and explain as best i can.
I ran a bath last pm (took about 10 mins). When i went to get towel from airing cupboard noticed major leak everything in airing cupboard saturated and floor in room.
i couldnt turn stop cock off so phoned landlord. He came out turned water off and proceeded to fix the problem.
He accused my fella of tampering with the ball valve thing in the tank - saying it had been turned. Is this possible as i thought they were screwed into place?
I know nobody touched anything in tank so what could have caused it, and more importantly im scared to death it is going to happen again - could it?
I hardly slept at all last night worrying about it - ran bath this am and it didnt hapn again but i watched the tank consistantly coz im worried its not fixed properly.
Thanks for reading this, any suggestions would be really appreciated
Fiona

Its difficult for me to immagine a situation where the valve could rotate on its own. I would guess that it was wrongly installed.

Being suspicious, there are sometimes other issues in these cases.

Could it be that the landlord does not like your boyfriend visiting you?

Tony

Thanks, i dont think he is bothered about my boyfriend.
Could anything else have caused the leak, like the ball being faulty or something?
im really worried its gonna happen again, my landlord didnt use ant tools to move anything and he isnt a plumber!

Without seeing it, its difficult to immagine what was wrong that could be properly fixed without tools.

Perhaps the valve is loose and had rotated on its own, the landlord just rotated it back again and its still loose?

My advice is that it should be checked by a plumber or a competent DIYer but as you are a tenant you probably dont want to pay the £50 or so for it to be checked by a plumber.

You will possibly have to accept the current situation.

Tony

Yes they can undo themselves if not tight and the arm isn't straight up/down.

Thank you

Sounds like it was a part 2 ball valve & the plastic bit on the top has come off making it look like it's upside down.