Hardie System All Zones On After Pipe Repair: Wire Damage

Post-Excavation Electrical Fault Diagnosis

After repairing root-cracked PVC near a 3-valve manifold on a Hardie HD 15 system, all 4 zones run continuously even in manual single-zone mode.

Cause: Damaged Control Wires

Excavation likely nicked or severed control wires between the controller and valves. This creates short circuits between zone wires and common, energizing all solenoids simultaneously.

Repair Protocol

1. Inspect excavation area for damaged wire insulation
2. Redo all wire connections at valves with waterproof gel-filled connectors
3. Test each zone independently at controller
4. Document splice locations with measurements from fixed landmarks

If wires are damaged underground, consider running new control wire in conduit rather than repairing multiple underground splices.