Display shows “Err5” and the unit will not initiate or complete a regeneration cycle.

Safety first: Ensure the unit is powered but not in the middle of a regeneration. Do not interrupt a cycle unless necessary; if you must, place the valve in bypass first.

• Enter programming mode: Follow the Hellenbrand manual to access installer or advanced setup. Verify that the system type (metered/time clock, single/twin alternating) matches the actual hardware.
• Verify key parameters: Check hardness, capacity, reserve, and regeneration time settings. Correct any obviously incorrect values (e.g., capacity set to 0, hardness set to 0).
• Restore factory defaults: If available, use the factory reset function to reload default programming, then re-enter site-specific settings.
• Check for stuck buttons: A stuck keypad button can cause programming errors. Press each button several times and ensure none are physically jammed.
• Board replacement: If Err5 persists after reprogramming and reset, the control board firmware may be corrupted. Replace the control board with a compatible Hellenbrand part.