I have seen no indication of the age of the equipment or that the softener resins are bad and in need of replacement. Do you any pictures of the equipment or a web link? .
The Master NS-10T combination acid neutralizer & softener (Pottstown, PA) is 25 years old. You can see photos of the head in my other post regarding the brine tank overflowing. From comments by others, it's an Autotrol valve. Having cleaned some screens in the head that hadn't been cleaned in 25 years, the water is now soft, but the brine level went a little higher in the tank after the back flush, so it looks like not all the brine is being sucked back during the cycle.
How long is the copper plumbing before the AN filter? Brass fittings?
No longer than 12". After the pin holes in the feed lines to the conditioner, I had the plumber put in Pex. There's roughly 3" of Pex to the conditioner and copper after it, except for the Pex line I ran directly to the kitchen sink. Even with the conditioner on the water system, we'd have a bitter (copper?) taste in the water in the morning when it had sat in the pipe for a long time. Running a Pex line to the sink with untreated water has corrected that.
What Gary said about flushing the acid neutralizer every 3 days is the conventional wisdom of the plumber here in PA who set up the unit 25 years ago. Since it's a combination unit, it eats salt, because that gets regenerated at the same time. We use at least 750 lbs of salt a year for water that unconditioned has only 3 grains / gal of hardness. Does anybody have any experience letting the AN regenerate on a longer cycle? If it channels, can it be easily broken up with a stick / bar through the fill hole on the tank?
A thought that just came to me. I could keep the current combination for its acid neutralizing capability and add a new metered softener downstream from that, if the softener wouldn't need to be regenerated on such a frequent schedule. Is back flushing on softeners strictly on the basis of using up the ions, or do you need to flush softeners on a more frequent schedule to keep them from caking / channelling too?