RD900 Zones 3,5,6 Intermittent – Common Wire Connection

Three zones fail together, worked again after week once before. No wiring knowledge.

Likely Cause

Bad common wire connection at controller or valve. Common wire daisy-chains all valves.

Fix

• Tighten common terminal at controller.
• Check all solenoid common wire nuts.
• One bad common connection kills downstream valves.