Fleck 5600 Piston Assy. Low Water, 560CD

The Fleck 5600 Piston Assembly, Low Water, for the 560CD control (FL60102-201, also cross-referenced as FL60102-20) is the moving piston that directs internal water flow through a Fleck 5600 valve. This low-water version is designed for applications with reduced water pressure, helping the valve cycle reliably where flow or pressure is limited, such as homes on well systems or areas with low municipal pressure.

Piston function and fit

• Piston assembly for the Fleck 5600 / 560CD control
• Low-water configuration for reduced-pressure applications
• Directs flow through service, backwash, brine, and rinse positions
• Genuine Pentair Fleck part; alternate number FL60102-20
• Core wear item that benefits from periodic replacement
• Helps maintain reliable cycling on well and low-pressure supplies

The piston is the central moving part of a Fleck control valve, traveling through the valve body to open and close the internal ports that define each stage of the cycle. Its precise movement and sealing are what route water correctly to backwash the bed, draw brine, rinse, and return to service. As the piston and its associated seals wear, the valve can develop internal leakage, leading to weak regeneration, salty water reaching the home, or a continuous trickle to drain that wastes water and salt.

The low-water variant is specifically suited to homes or systems on well or low-pressure supplies, where a standard piston might not cycle cleanly because there isn't enough pressure to move it reliably through every position. Matching the piston to your supply conditions is the key to dependable operation in those settings.

When replacing the piston, it is best practice to install a fresh seal and spacer kit at the same time, since the two wear together and a new piston seals far better against new seals than against old, grooved ones. Apply a light film of silicone lubricant to ease installation and protect the parts as they slide into the valve body. Place the valve in bypass, relieve pressure, and disconnect power before opening the control head. The correct low-water 5600 piston restores crisp, reliable cycling even in challenging-pressure conditions. Choosing the low-water piston for well or low-pressure supplies, and pairing it with fresh seals, is the dependable way to keep a 5600 cycling cleanly where a standard piston might hesitate or stick.