Hunter ICC-800PL "16 ERR": Ground Fault on Zone 16 Wiring

Hunter ICC Shows "16 ERR": Zone 16 Wire Has Ground Fault

Zone 16 valve works manually, but controller faults. Other 4 valves in same box work fine.

What "16 ERR" Means

Controller detects current leakage to ground on Zone 16 output. Could be:

• Nicked wire insulation touching earth.
• Solenoid internal short to ground.
• Water in wire splice (corrosion path).

Continuity Test Procedure

1. Unplug controller. 2. Set multimeter to OHMS (Ω), lowest range (x1 or 200Ω). 3. Disconnect Zone 16 wire at controller. 4. Probe: one lead on Zone 16 wire, other on ground rod / bare copper ground wire. 5. Reading ∞ (OL) = good. Any numeric reading = ground fault.

If Wire Tests Clean

Test solenoid: disconnect at valve, measure solenoid coil resistance (should be 20–60 Ω). Then test each solenoid lead to valve body (ground). ∞ = good.

Fix

• Faulty wire: replace section or re-splice with waterproof connectors.
• Faulty solenoid: replace (take old one to match).

Hunter ICC fault detection is sensitive—fix the ground leak, error clears.