Control valve will not start regeneration; display shows E01 and unit remains in service mode.

Safety first: Unplug the Crystal Quest softener from power and close the inlet water valve before opening the control head. Depressurize by running a nearby faucet until flow stops.

• Power reset: Plug the unit back in, press and hold the REGEN or SET/REGEN button (model dependent) for 5–10 seconds to attempt a manual regeneration. If E01 reappears immediately, proceed.
• Inspect motor wiring: Remove the control valve cover. Check the small drive motor on the Crystal Quest control head. Ensure the 2‑wire or 4‑wire harness is fully seated on the motor and on the main PCB. Look for corrosion or burnt connectors.
• Check for mechanical binding: With power disconnected, gently try to rotate the main drive gear or cam by hand (if accessible). If it will not move or feels gritty, the piston/seal/spacer stack may be seized. Do not force it; this can strip gears.
• Test motor operation: Restore power with the cover off, then initiate a manual regeneration. Watch the motor: if it hums but does not turn, or does not energize at all, the motor is likely failed.
• Corrective action: If the piston is stuck, rebuild the valve with a Crystal Quest piston and seal kit. If the motor does not run or the gear is stripped, replace the Crystal Quest control valve drive motor assembly. Reassemble, restore water and power, and run a full regeneration cycle to confirm normal operation.