Hunter Pro-C "Err" on Zone 3: Solenoid vs. Wiring Diagnosis

Fixing "Err" Errors on Hunter Pro-C Controllers

When Zone 3 shows "Err" and counts down from 34, the controller detects a short circuit or excessive current draw on that station. Other zones work fine.

Step 1: Isolate the Fault

1. Remove the Zone 3 wire from the controller terminal.
2. Run a manual cycle on Zone 3.
3. If "Err" disappears: Fault is in the field wiring or solenoid.
4. If "Err" persists: Controller internal fault—try a full reset (remove battery + AC power for 3 min).

Step 2: Solenoid vs. Wire Test

1. At the valve box, disconnect one wire from the Zone 3 solenoid.
2. Run Zone 3 manually from controller. 3. If "Err" clears: Solenoid is shorted—replace it. 4. If "Err" remains: Field wire has a short to ground or another wire.

Finding a Replacement Solenoid

• Unscrew the old solenoid (usually ½ turn counterclockwise) and take it to the store.
• Match brand, thread size, and plunger type exactly.
• For Hunter valves, Orbit brand solenoids (sold at Home Depot/Lowe's) are often compatible—Hunter owns Orbit.

Pro Tip

Before buying, measure solenoid resistance with a multimeter (ohms setting). A healthy 24 VAC solenoid reads 20–60 ohms. Near 0 ohms = shorted; infinite = open coil.