Display shows “Err4” and the softener does not respond to button presses or time-of-day is lost frequently.

Safety first: Disconnect power before removing the control panel. Avoid static discharge by touching a grounded metal object before handling the board.

• Power cycle: Unplug the unit for 5 minutes, then reconnect. Reprogram the time and regeneration settings. If Err4 reappears quickly, the board is likely failing.
• Check power supply: Verify the Hellenbrand power adapter is outputting the correct voltage (typically 12–24 VAC depending on model). Use a multimeter at the transformer output. Replace the transformer if voltage is low or unstable.
• Inspect board for damage: Remove the control cover and visually inspect the PCB for burn marks, swollen capacitors, or corrosion from moisture. Any visible damage indicates the board should be replaced.
• Secure connections: Ensure all harnesses are firmly seated on the board headers. Loose connections can cause intermittent memory and clock errors.
• Replace control board: If power is good and wiring is secure but Err4 persists, replace the Hellenbrand control board with the exact model-specific part. Transfer any jumper settings as per the installation manual.