Irritrol Controller Loses Time: Battery or Short?

Symptom: Time Resets Erratically

An Irritrol 9-station controller that won't hold time usually has a missing or dead backup battery or a shorted zone circuit that resets the microprocessor.

First Checks

1. Ensure a fresh 9 V alkaline battery is installed.
2. Check for "SHORT" or "FUSE" messages on display.

If Battery Is Good

A shorted solenoid or wire on any zone can cause the controller to brown-out and lose time. Disconnect all zone wires, power up with battery, and see if time holds. Reconnect zones one by one to isolate.

Model Number Needed

Provide the exact model (e.g., RD-600, RD-900, MC-900) for specific troubleshooting steps.