Hunter Pro-C Master Valve Not Activating for Stations 1-3

System: Hunter Pro-C with two 3-station modules (9 stations total), PGV valves with master valve, wireless rain/freeze sensor. Master valve clicks and runs for stations 4-9 but not 1-3. Station valves 1-3 click and flow water if master valve is manually opened.

Checklist

1. Programming – Verify the Pro-C is set to activate the master valve (MV) for stations 1-3. The MV must be enabled per station in the controller.
2. Module seating – Ensure the add-on module for stations 1-3 is fully locked in place; a loose module breaks the MV signal.
3. Module failure – If programming and seating are correct, the module itself may be defective.

Confirm MV programming for zones 1-3 and reseat the module. If the problem persists, replace the module.