Something many homeowners don't realize is that Des Moines Water Works already softens water at the plant with lime, and West Des Moines Water Works does the same. Even after that treatment, West Des Moines Water Works reports an average tap water hardness of about 9 grains per gallon. That's still hard enough to scale a water heater and spot every glass in the cabinet. Your home softener finishes the job the utility starts. However, that job wears on the equipment.
City water carries chlorine or chloramine to keep it safe, and over the years those disinfectants break down the resin beads inside the tank. Iowa winters add their own trouble. A softener in an unheated garage or a cold corner of the basement can freeze and crack its valve body or brine line, the same kind of damage we see on frozen pipe repair calls every January. Humid summers bring salt bridges, a hard crust in the brine tank that looks full but leaves the resin with no brine to recharge.
The early warning signs are easy to miss. A water bill that creeps up is a big one, because a unit stuck in regeneration sends water down the drain all day. West Des Moines Water Works lists a malfunctioning softener as one of the most common reasons for a jump in usage. Soap stops lathering. A white film shows up on the glass shower door. Catch it at that stage, and it's usually a one-visit fix.