I need to water my zones at the same time so that my water well pump doesn’t turn on and off as much, which would wear it out.
It’s not obvious to me how to set Rachio to do this.
What is maximum zones Rachio 3 can water at same time?
Rachio can’t/won’t water any zones at the same time, but you can wire up to 3 zones (combination of zones and master valve OR pump). In your case of having a pump that is presumably on a pump start relay, you can wire 2 zones together.
Otherwise, you can probably also activate the water hammer feature, which will overlap the zones as they switch throughout the schedule.
But with your well, do you not have a pressure tank with it?