bought af-40k water softener made by watts premier (the name brand though they bought it from someone else) from costco; lasted 2 years; called Premier for service; they don't do any; called for parts to diy; they can only get the optical sensor (which is not the problem); can get a controller for it which is so expensive its not worth it; costco should not use this company; the company can't even keep a water softener unit going for 3 years; the receptionist (also known as the "technician" offered some suggestions on cleaning and sanding stuff); all the suggestions failed; I feel I've been totally ripped off; $400 for the softener; plust $200 for installation and now I've got a $600 piece of garbage in my garage; nobody seems to have even heard of this model softener (made by Pentek) on the internet