Culligan High Efficiency 1.5 Twin Series Installation, Operation And Service Instructions page 59

Refill
To make the brine, water flows into the salt storage area during the fill stage. Fill cycle length depends on the salt dosage.
Use soft water for refill.
Raw
Water
Cat. No. 01024821
P6
P1
P2
P3
Figure 58. Down flow regeneration—refill.
Refill
Piston
P1–Inlet
P2/3–Outlet
P4–Backwash
P5–Rinse
P6–Bypass
Brine Piston
PR–Refill
Tank
Inlet
P4
Brine
Piston
Soft Water
to Fill
Brine Tank
PR
P5
Tank
Outlet
Position
Open
Open
Closed
Closed
Closed
Closed
Open
To
Drain
To
Brine
Tank
Hard Water
Softened Water
Drain
Brine
Diluted Brine
Troubleshooting 55