OpenSprinkler › Forums › Hardware Questions › OpenSprinkler › water refilling system for tank › Reply To: water refilling system for tank May 31, 2016 at 9:19 pm #42727 pbParticipant Or use a traditional ballcock inside the tank as well as the solenoid. Thus, both the solenoid and ballcock must be open for water to flow. This doesn’t help the dry pump start case.