Hi. Good suggestion but it’s not over filling. It seeps when it’s full and not when 2/3rds full!
I’ve checked all the lower outlets and they are all dry.
My 50 gallon cold water tank in the loft has sprung a seeping leak. It only leaks if completely full so I am currently part filling it!
It’s got 3 outlets - hot water tank, shower pump and a possibly unused one to a pre shower pump fitted gravity shower feed.
Can a reasonably competent DIYer...