Ball valve is underwater

[Lee2727]

Any help would be great, I've got boiler and a immersion tank down stairs,
Just looked in loft and noticed the float ball is underwater,
I have to tanks in loft 1 most be for my hot water/taps that's the the big tank, then above that I have a small tank which I believe is for heating. I believe I'm right
Does the ball just need changing, plus I have white gunk on top, thank you for any advice would be appreciated.

 

[Dangee]

Depends, unscrew or judge for yourself if the float is full of water. If it is, change it . If not, rewashere/change the ballvalve.

 

[Razor900]

Drain the excess water out of the cistern whilst holding the ballvalve up to keep it closed. Preferably tie it up.

If the ballvalve doesn't drip and the cistern refills over a couple of hours you may well have a leak in the cylinder coil