Setting: Model Code, 12 or 24 Hour Clock and Gallons or Liters Measured
Model Code: The timer must have the right model code set to operate the water softening system correctly. The correct code setting for the GNSF39A is
If 
is flashing in the display, do steps 3, 4, 6 and 8 below.
To check for the correct code setting for your model, and to reset it if needed, do steps 1, 2, 3, 4, 6 and 8 below.
NOTE: The hour clock and water measure have factory set default values. The defaults are: 12 or 24 hour clock
12 or 24 Hour Clock: With 12 hr set, all time displays are in standard clock time …12:00 AM to 11:59 PM. If 24 hr is set, time displays are in military time …0100 (1:00 AM) to 0000 (midnight). To change from the 12 hr setting, do steps 1, 2, 4, 5, 6 and 8.
Gallons or Liters Measure: All water flow rate and usage displays are in gallons with the default
setting. If reset to 
, the same displays are shown in liters. Use steps 1, 2, 4, 6, 7 and 8 to change.
1
2
3
4
5
6
7
8
Beginning from the present time display, press and hold in the SET button until RECHARGE TIME 
AM (or as otherwise set) begins to flash.
Press and hold in the SET button again.
If setting is other than
Press the SET button again and | TIME | flashes. |
To change the display to 
use the UP button. Use the DOWN button to reset to 12 hr.
TIME
Press the SET button and 
flashes.
Use the UP button to change to the 
setting. Use the DOWN button to return to the gallon setting.
Press the SET button a final time to return to the present time display.
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