My heart always sinks when I have a call from a customer that have a 'salt free water softener'.
They always say can you test it as it is not working we still have loads of scale.
These units are not softeners, there is no test to see if they work and every customer will tell me they still have loads of scale.
All I can do is offer them one of our proper water softeners on a sale or return basis. Our Softeners work . Call if you want to try one, no strings.