drip from expansion tank frozen

[Gary111]

hi, my expansion tank overflow has been dripping, i didnt get round to fixing it.
now the drip has turned into an icicle, hence stopping the water escaping.

the ball valve is fully submerged
(i also noticed a rainbow like colour in parts of the tank as if there was something oily ??)

im guessing i need to bail it out then replace the float valve

but theres also a larger tank next to it , the float valve is dripping on that one but its nowhere near getting full.

im not sure how these tanks work, could that be causing the smaller tank to overflow ?

any ideas please
thanks

 

[muggles]

Sounds like you need two new float valve. The smaller tank fills your heating system, the larger one fills your hot water cylinder. If the larger one is causing the smaller one to fill, you'll need a new hot water cylinder