The following is a list of possible error code problems and their solutions for a commercial CUC2 unit.
Offline units with error codes are unaffected. Error codes are shown in the normal run displays. The operator must press the RECHARGE key to clear the error code and place the unit back online.
The self-diagnostics checks certain items during normal operation. It indicates a condition to the user that would inhibit the system from providing soft or filtered water. The items checked in self-diagnostics are:
| No Error | ERROR 0 |
| Motor not running, or position switch bad | ERROR 1 |
| N/A - Does not occur on this product | ERROR 2 |
| Timing error | ERROR 3 |
| Motor on continuously | ERROR 4 |
| Microprocessor bad | ERROR 5 |
| Recharge does not clear immediate recharge switch | ERROR 6 |
The controller performs Error 1 and 3 checks during the recharge process. Error 4 is checked during a two-minute interval following the command to stop the motor. Error 5 is checked once every minute. Error 6 is checked for the 3-minute interval following a complete system recharge initiated by the immediate recharge switch. When an error condition occurs, the display shows an error message. The error message overrides any primary function display until the error condition clears, then the display returns to normal.
ERROR 1
Error 1 is displayed 8 minutes after the controller commands the motor to drive, and no position switch transition is sensed. First, the motor is turned on for 4 minutes and if no position switch is found, the motor is turned off. Next, the motor is turned on again for another 4 minutes and if no position switch is found, the Error 1 message is displayed and the unit is taken offline. The possible causes are:
| Error 1 Problem | Solution |
| Bad motor | Replace motor |
| Bad position switch | Replace position switch |
| Bad cable to position switch | Replace cable to position switch |
| Bad output drive circuit to motor | Replace face plate |
| Bad cable or connector to motor | Replace motor |
| Bad position input circuit | Replace face plate |
| High torque valve | Replace or repair valve |
ERROR 3
Error 3 is displayed if the controller cannot find the service position after a recharge. After one complete revolution, the longest detent time should be greater than 1.5 times the length of the second longest detent time. If this statement is not true, one or more revolutions are done searching for this condition. The motor is shut off and the unit is taken offline if the condition cannot be met.
| Error 3 Problems | Solution |
| Bad cable to position switch | Replace cable to position switch |
| Bad position input circuit | Replace face plate |
| Bad motor | Replace motor |
| Wrong valve selected | Reconfigure system |
| High torque valve | Replace or repair valve |
ERROR 4
Error 4 indicates that the motor is running continuously. The Error 4 message is displayed if a change in the position switch from closed to open is sensed within two minutes after the motor was commanded to stop. When an Error 4 is detected, the unit is taken offline.
| Error 4 Problems | Solution |
| Bad position switch | Replace position switch |
| Bad cable to position switch | Replace cable to position switch |
| Bad position input circuit | Replace face plate |
ERROR 5
Error 5 is displayed if the microprocessor detects a failure with some of its RAM cells. The cells are checked once per minute. When Error 5 is detected, the valve is advanced to the service position if it is not already there. It remains there as long as the Error 5 condition exists.
| Error 5 Problems | Solution |
| Bad controller | Replace face plate |
ERROR 6
Error 6 is displayed if the immediate regeneration line is closed for 3 minutes without a valid open (switch open for 15 or more seconds) after a complete system recharge (all online service tanks regenerated).
While the Error 6 code is displayed, demand systems (softeners and filters with Filter Gallons not set to "Off") continue to recharge based on the normal rules. The immediate recharge input is ignored. Recharges of filter systems may occur more frequently based on the value set for Max Days between Recharges. If that setting is Auto, the system will recharge every day.
If the Error 6 code is cleared and the immediate recharge line is still closed, the system goes into another recharge. Once the error code is cleared, the system returns to its normal recharge cycle.
Error Code Indications
Error codes are displayed in screens similar to the one shown below. If more than one error occurs, the latest error found is displayed.