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Hardie 446PR Display Garbled: Reset or Replace

Fixing a Corrupted Display on Hardie 446PR

A display showing "6" followed by blanks and an inverted "U" after programming indicates a microprocessor glitch or failing LCD driver—common in aging Hardie controllers.

Reset Procedure

Remove the 9 V backup battery.
Disconnect AC power for 60 seconds.
Reconnect AC power without the battery.
Observe display: if it reads normally, reinstall battery and reprogram.

Replacement Recommendation

If the display remains garbled, the controller is not repairable. Hardie (now Irritrol) discontinued this model. Direct replacements:

Irritrol Rain Dial (RD-600, RD-900, RD-1200) – same wiring footprint, modern features.
Rain Bird ESP-TM2 / ESP-Me – widely available, excellent support.

Both install in 30–60 minutes using existing field wires.

Irrigation: RD‑900: Three Stations Work Intermittently – Circuit Board or Wiring Fault?; Hardie 9‑Station Controller Replacement: Irritrol Rain Dial; Hardie Irrigation System Runs Continuously: Valve vs Controller Diagnosis; Hardie RJC-FOUR Controller: Obsolete Model Replacement Options; Hardie RD-600 Display Frozen After Power Outage: Controller Failure; Hardie RD-1200 Battery Drain: Replace Panel, Not Whole Controller; Hardie Controller Manual Station Error: Replace Panel or Upgrade to Rain Dial; Reviving or Replacing a Legacy Hardie HHA 11272 Controller After Power Outage; Hardie Controller Runs Continuously: Valve or Controller Fault?; Hardie HR6200 Fuse Holder Replacement: Contact Irritrol (Toro)

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