Troubleshooting Aquamaster High Efficiency Water Softeners that is showing a blank display on the controller.
Check the obvious first! Remove the valve cover for access.
1) Is the water softener plugged in? Check that the transformer is plugged into the controller. Make sure there is electric power at outlet. Make sure the outlet is not controlled by a switch
2) Is the transformer defective? Test with volt meter for 12 VAC at control. If less than 10 VAC or greater than 14 VAC, replace the transformer
3) Defective circuit board? With 12 VAC present at controller, replace the controller
4) High ambient room temperature? If the temperature exceeds 120°F, the display will blank out. This does not affect the operation of the controller No action necessary.
Note: Like any quality electronic device I recommend you plug all of your water treatment equipment into a surge suppressor like this one to protect it from power surges, it's cheap insurance!