The short answer
A salt bridge (a crust over a hollow), mushy salt at the bottom, or a valve that isn't drawing brine are the usual causes.
Check in this order
- Push a broom handle down through the salt: if it hits a hard crust with space below, it's a bridge; break it up.
- Look for mushy salt at the bottom; scoop it out and refill.
- Run a manual regeneration and watch whether brine is drawn down.
- If not, clean the injector screen and nozzle and check the brine line.
Preventing it
- Keep the salt level a few inches above the water, not packed to the top in humid spaces.
- Use clean pellets such as Morton 1499 25 lb Softener Salt Pellets; residue builds faster with lower-purity salt.
Parts that fix it
Safety floats Fleck 60102-00 Brine Float Assembly and valve parts in the lookup.
Products mentioned
Questions readers ask
Why is my water softener salt not going down?
Usually a salt bridge or a valve not drawing brine; check for a crust first.
How do I fix a salt bridge?
Break the crust gently with a broom handle, remove loose chunks, and refill with clean salt.