Sprinkler heads popping up and down.
The sprinkler system we have in our house was here when we bought it.
The control panel is a hunter control panel with everything else being Hunter except for the valves and solenoids.
Not all zones but at least 3 of the 10 have an issue where the heads pop up and down when it's their turn to turn on.
Just to see if it was the diaphragm or the solenoid, I replaced both on zone 10; one of the zones having the issue. After replacement the issue still exist.
What could be the problem and what could be the next step.
I can hear the lines under the ground making noise as well when the heads are popping up and down.
TIA