Water softener not regenerating

1. Bypass valve. It may have been left in bypass.
2. Power and clock. An outage can reset a timer.
3. Salt bridge. Push a broom handle gently into the salt. A hard crust can stop brine forming.
4. Salt level. Keep the tank at least a quarter full.

If those are fine, the likely causes are a clogged injector, a failed motor, or a worn valve. A service call is usually $40 to $100 before parts. All repair prices.