Toro DDC Controller: Zone 1 Runs with All Other Zones – Wiring Fix

Zone 1 running simultaneously with zones 2–6 on a Toro DDC controller typically means zone 1 is wired to the Master Valve (MV) or Pump terminal instead of a zone terminal.

Fix

1. Open controller; check terminal strip.
2. Ensure field wires connect to zone terminals (1, 2, 3…), not MV, Pump, or Sensor.
3. Common wire (usually white) must be on "C" or "Common" terminal.
4. If master valve/pump exists, wire it to MV/Pump terminal only.

Tools Needed

Small screwdriver, wire stripper. Re-secure all connections with waterproof wire nuts.