Hunter ICC-800 Random Station Cycling: Test for Phantom Voltage

If your Hunter ICC-800 randomly activates stations (no schedule, no errors, Quick Check passes), the controller is likely sending phantom voltage. Reset didn't help — next step: measure voltage during ghost cycles.

Diagnostic Test

1. Wait for random pop-up.
2. Measure at controller: black lead on Common (white wire), red lead on each station terminal.
3. If voltage present (24+ VAC) when station should be OFF → controller is defective.
4. If no voltage → check for induced voltage from nearby wires (rare).

Why Reset Failed

Microprocessor or relay driver latch-up — not cleared by power cycle. Battery removal + power down for 15 min should reset RAM, but if output drivers are fried, it persists.

Action

Replace controller. Hunter ICC series is discontinued; upgrade to ICC2 or HCC (Wi-Fi).

Pro Tip

Before replacing, verify no master valve/pump start relay wiring is shorted — but random multi-station activation points to controller.