I don't know if this will help or not, but here goes. I have a Kenmore water softener, and every 2-3 years need to open up the valve assembly and replace the "rotor and disc." This year I also replaced the venturi and gasket.
I had a similar problem to you, although the water level never filled the tank -- would come up to the 10" float height, no higher, but then would never drain out since the unit wasn't able to draw brine.
I don't know if Ecowater systems are similar to the valves used in Kenmore units, but you could check out www.kenmorewater.com and run their troubleshooting animation. I found it EXTREMELY useful in diagnosing and fixing mine.