It sounds like the meter or senor is not working. If you don't have a manual, you might find it here: http://www.pentairwatertreatment.com...ControlValves/
I have a softener with a 5600se valve on it, and it seems like I'm not getting soft water. I purchased my home about a year ago, and for about the first few months, everything seemed to be working properly, but then the salt level stopped going down in the brine tank, and about the same time, I also started seeing hard water residue forming on faucets and such.
I thought perhaps it might be a salt bridge at the bottom of the brine tank, so earlier this week I emptied it out, cleaned it out as well as I could, and replaced all the old salt with new System Saver II pellets, and forced a regeneration cycle. Since then, I've been checking the indicator on the front, and despite us using water as normal (showers, doing laundry, using a dishwasher, etc.) the "volume remaining" of softened water has remained at the post-regeneration level of 650. The bypass valve is set to "service" and the "flow" light is on.
you can remove the sensor from the meter assembly. Run a small magnet up and down and see if the flow indicator light blinks.
If it does. then your meter might not be functioning. The meter in the 5600/2510, etc, are fairly simple and relaible, but they are also expensive to replace.
How to rebuild a softener http://www.youtube.com/watch?v=8YkJS...ature=youtu.be