Condensation on toilet tank

Hi

I am new to the forum. We have a toilet tank that has condensation issues? We have a total of 3 toilets but this is the only one with sweating issues. It also seems as though the water in this tank is much colder than the other two, how is that possible? The tank has a liner in it already and it seems fine.... How can i fix this issue?

Nitu

That would normally indicate that water is leaving the tank, and it's constantly being refilled with fresh, cold water.

Sometimes it's as easy as replacing the flapper.
Or it could be that the refill tube is placed inside the overflow tube, causing the fill valve to siphon into the bowl.