Had changed cold water header tank valve from floating ball valve to plastic quieter vertical float valve. Overflow leaking again and about to change valve, but considering fitting a ball float valve as this seemed more robust though noisier. Am I right in this assumption?

Harry, January 2009

A good valve should work well whatever type it is. Is the float level set properly? Even a ball valve with cause overflow if it isn't.

LJB, January 2023