Step 1: Diagnose a resin bed problem
If your water softener doesn't put out any soft water or it regenerates and runs out of soft water quickly (in just a day or so), you probably have a damaged “resin bed.” A resin bed normally lasts 10 to 15 years. But iron in well water and excessive amounts of chlorine in city water can “kill” a resin bed. How do you know if your resin bed has “checked out”? Simple. Check to see if your water softener is using up salt at its regular rate. If it is, and you have no soft water, the resin bed has probably become saturated with iron deposits or been damaged by chlorine and can no longer be regenerated by the brine. If it isn't using much or any salt, the problem is most likely a bad valve head, meaning the resin bed isn't getting recharged with brine water at all. We won't cover that fix here.
First try using iron removal chemicals to clean the resin bed. (Type “water softener” in the search box above for more information.) This step won't help a damaged resin bed.
Figure A: How a Water Softener Works
Hard water enters from the valve head and flows down through the resin, exchanging hardness ions for sodium ions. The soft water flows up the riser tube to your plumbing fixtures.
Step 2: Replace the resin bed
If cleaning doesn't work, you'll have to replace the resin. You can do that yourself. It will cost you about $100 and save $150 in service fees. Figure about four hours to complete the job.
Start by measuring the resin tank to determine how much new resin you'll need (see “How Much Resin to Use”). Then contact a local water treatment company or shop online for the right high-quality resin (avoid the really cheap stuff) for your particular application. Also purchase a resin funnel, a new riser tube and gravel (if recommended for your system).
Next, rotate the softener valve to the bypass position (or turn off the main water valve). Turn the dial on the valve head to start a manual regeneration (that'll bleed off internal water pressure). Then disconnect the softener from the plumbing and electrical (Photo 1). Unscrew the valve head and set it aside (you may need a helper to hold the resin tank while you twist). Dump out all the resin and gravel (Photo 2).
Before you install the new resin, cut the new riser tube to the same height as the old one and insert it into the resin tank. Refill the softener (Photo 3). Then reinstall the valve head and reattach the unit to the bypass valve. Turn the valve back to the “in-service” position and check for leaks. Enjoy the soft water.
How Much Resin to Use
Measure the diameter (the circumference divided by 3.14 equals the diameter) and the height of your resin tank. Then refer to this chart to find how much resin you'll need. Never fill a resin tank to the top—it'll restrict the flow of water.