Error Code E14 is caused by tripping a high-limit snap switch on the tank body when the water is heated to 158F. This happens when the temperature is set too high, or more likely changed and not saved so the value is floating or non-existent. Be sure to press the SET icon after making temperature changes.
The fix is to use some hot water or let the tank cool down so the snap switch can reset itself. The bi-metal will automatically reconnect below 130F (55C) range. More important is to find out why the switch was manually turned to on "I" when it should always be in off "O"
This work-around manual switch fix was resolved by integration into SP3.0 controller. It is limited to one batch of SP2.3.
O is Off and the default position.