If you get this error start work with the following conditions :
1- DI pressure switch does not change when power turned on. 2- DI pump is not ON or water pump does not work.
3- DI pressure switch not actuated or flow switch malfunction .
4- The water flow is blocked .
⚠️ If this information is not enough or you are still facing the same problem, do not hesitate to leave your inquiry in a comment .