Toro 6‑Zone Lake‑Fed System: Multiple Zones Fail After Dewinterization

After dewinterizing, zones 3, 4, and 5 malfunction. Zones 3‑4 initially worked only with manual valve opening; now zone 4 fails completely. Zone 5 failed entirely. Wire swapping suggests the controller outputs are fine. Voltage testing shows 24 VAC on the red wire but not on the white (common) wire at the valve box.

Analysis

• The common wire (white) likely has a break or poor connection in the valve box.
• Solenoid buzzing on zones 3‑5 indicates the controller is sending voltage, but the valves aren’t opening fully due to insufficient voltage across the solenoid (common path broken).
• Replacing the zone‑5 solenoid didn’t help, confirming the issue is wiring, not the solenoid.

Repair Steps

1. Inspect and repair the common wire in the valve box (use waterproof grease‑filled connectors).
2. Test each valve by opening its bleed screw; if no water flows, the diaphragm may be lodged in the valve body.
3. Rebuild valves with new diaphragms if needed (irrigationtutorials.com).

A single solenoid cannot control two zones independently; zones 5‑6 share a valve body with two solenoids? Clarify valve configuration.