Overview: Check the control settings
Is your soft water not so soft anymore? You can often fix the problem yourself. However, if you have an older softener (20 years or so) and none of these fixes work, it may need replacement ($500 and up).
All softeners, whether they have one or two tanks, work the same way. As cold water flows through the resin tank, the mineral content—the hardness—is removed because the minerals stick to thousands of resin beads. When the softener recharges, the flow of fresh water is stopped while salty water from the brine tank is sucked into the resin tank, where it dissolves the accumulated minerals and is flushed down the drain.
Before you tear apart your softener, check the control settings—especially after a long power outage. The timer clock has to show the right time so that the resin tank is cleaned and recharged when no one is using water (usually early morning).
Also make sure the hardness setting is still correct—well water hardness can change over time. Bring a small container of your water to a water softener dealer for a water hardness test, then check the results against your settings.
Note: Set the water supply to “bypass” before working on the softener. And run the hot water after you turn the softener back on to flush out any hard water.
Step 1: Look for salt problems
Check for salt problems in the brine tank. Start by pushing a broom handle down into the salt to break up salt bridges (like a dome), blocking salt from dropping to the bottom of the tank. If too little salt gets dissolved, the resin bed won't get clean and the water won't get softened.
Also, when the salt level is low (or at least once a year), check for a crust of salt mush at the bottom. This thick salt paste doesn't dissolve well, reducing the salinity of the brine solution, and needs to be removed (photo).
Don't use rock salt; it contains dirt and other impurities that can clog the softener.
Step 2: Clean the resin bed
Clean the resin bed twice a year with resin bed cleaner (available at water softener dealers) if you have “clear water iron” (dissolved iron makes a glass of water turn cloudy or rusty after sitting for several minutes). Otherwise the resin bed won't remove the iron (photo).
Step 3: Clean the venturi assembly
The salty water flows through these parts from the brine tank to the resin tank. If the screen and nozzle get clogged by sediment, the resin bed won't be cleaned and the water will stay hard (photos).