Zone 2 Won't Activate on Hunter SRC+? Check the Common Wire

On a 3-zone Hunter SRC+ system where zone 2 only works when the solenoid is manually unscrewed, the problem is almost always a broken or disconnected common wire to that valve.

Why the Common Wire Matters

Each solenoid needs two conductors: a zone wire (hot) and a shared common (white). If the common is severed, the circuit is open — no current flows, no magnetic field, no valve opening.

Diagnostic Checklist

• Measure 24 VAC at controller: zone 2 terminal to common terminal → should read 24–28 VAC.
• Measure at valve 2 solenoid: same reading? If not, wire is damaged between controller and valve.
• Inspect all splice points in valve boxes — look for corrosion, loose wire nuts, or severed conductors.

Why Other Zones Work

Zones 1 and 3 share the same common wire but have intact connections. Zone 2's common leg is broken downstream of the last working splice.

Fix

1. Locate the break using a wire tracer or by inspecting each splice.
2. Repair with waterproof connectors (e.g., 3M DBR/Y-6).
3. If wire is damaged in conduit, pull new common wire.

Don't replace the controller or solenoid until you verify the common wire continuity.