Display shows “Err 3” and the valve will not complete a regeneration cycle.

Safety first: Unplug power and place the valve in bypass before disassembling. Depressurize by opening a nearby faucet.

• Check water pressure: Ensure house pressure is within Fleck specifications (typically 20–125 psi). Very low pressure can cause slow or incomplete cycles.
• Inspect for mechanical binding: Remove the valve cover and check that the cam and piston move freely. Look for broken parts or foreign objects.
• Service piston and seals: Remove the main piston assembly and seal/spacer stack (per model instructions). Inspect for scoring, swelling, or debris. Replace with a Fleck piston and seal kit if worn.
• Evaluate resin bed: If the tank is heavily fouled with iron or sediment, backwash may be restricted. Consider a full resin bed cleaning or replacement.
• Test drive motor: If the motor stalls under load but runs freely without the piston, replace the drive motor.