The average water softener system lasts about 10 to 15 years, according to SaltlessWater.com. Salt-based systems can last up to 20 years if well maintained, and salt-free water softeners may last even longer than that.
If a water softener is not performing well or needs expensive repairs, it may be time to replace the system instead of repairing it. If the problem is simply that resin beads need to be replaced, this is a relatively inexpensive fix. However, it may be more economical to replace a system that is more than 10 years old or made of inexpensive materials. Salt-free water softener systems are a newer technology, so less information about their life spans is available. However, they are usually designed more simply and may need fewer expensive repairs.