Quick answer from a licensed plumber: Same valve body, different head. A Fleck 5600 has a mechanical dial timer with a skipper wheel and a knob you turn to start a regeneration; a 5600SXT has a digital display, an Extra Cycle button, meter modes and an 8-hour power backup. The wearing parts in the body are shared: injector (sized to the tank, #1 white for 9- and 10-inch tanks), injector screen, brine valve, BLFC and DLFC washers, with the piston chosen by its end-plug color from the 5600 manual. The powerhead, timer, motor and meter are not.
How to Tell Them Apart
Both are the same 5600 valve body with different heads. Pentair’s service manuals describe the difference in the way each is set:
| Fleck 5600 (mechanical) | Fleck 5600SXT (electronic) | |
|---|---|---|
| Head | A dial timer. The manual’s job sheet asks for “Type of Timer: A. Time Clock B. Meter Initiated,” and the time-clock version sets its schedule by “sliding tabs on skipper wheel” | A digital display with buttons. The SXT “Parameter Display displays the current cycle step” and the settings are two-letter codes (TD for time of day, RT for regeneration time, H for hardness, C for capacity) |
| Starting a regeneration | Turn the manual regeneration knob (part 14177 in Pentair’s drive assembly list); the manual says to “Turn the manual regeneration knob slowly in a clockwise” direction and “Always allow the motor to stop before” going on | “Start an immediate regeneration by holding the Extra Cycle button for five seconds” |
| Metering | Optional mechanical meter (“MODEL 5600 METERED”), or none on the time-clock model | Meter input on the head; the SXT is set for the meter type: “t0.7 3/4-inch Turbine Meter,” “P0.7 3/4-inch Paddle Wheel Meter,” up to 2-inch, or “Gen Generic or Other Meter” |
| Power loss | Not covered in the 5600 manual excerpts we read | “Power backup that continues to keep time and the passage of days for a minimum of 8 hours”; it “does not monitor water usage during a power failure, but it does store the volume remaining” |
| Regeneration modes | Time clock or meter | “Meter Immediate,” “Meter Delayed” (codes FI and Fd), plus day-of-the-week and time-clock options |
If the head has a knob you turn and a wheel with tabs, it is the mechanical 5600. If it has a small screen and an Extra Cycle button, it is the SXT. Pentair also notes that a 5600 that “came with a separate electronic timer service manual” should be worked from that manual, which means some 5600 bodies carry an electronic timer that is not the SXT.
What They Share: The Valve Body and Its Wearing Parts
The 5600SXT manual’s control valve assembly lists the body and the parts that wear, and the 5600 manual has its own “5600 VALVE ASSEMBLIES” section; the numbers below are from the SXT list, so confirm each against the 5600 manual before ordering for a mechanical head:
| Part (Pentair 5600SXT manual) | Part number | What it does |
|---|---|---|
| Valve Body Assy, 5600, Downflow, w/TOT O-ring | 61400-12 (body alone: 19700-10) | The body both heads bolt to |
| Injector, Drain Assy, 5600 | 60084-0001 (#0, blank DLFC, .25 BLFC); 60084-0002, -0101, -0102 for other combinations | Draws brine into the tank; the nozzle and throat inside are sized to the tank diameter |
| Nozzle and throat, #1, White (9” & 10″ Tank) | 10913-1 and 10914-1 | The size in most 9×48 and 10×54 softeners; #0 Red is for an 8-inch tank, #2 Blue for 12-inch |
| Screen, Injector | 10227 | The screen that clogs first when a brine tank is dirty |
| Brine Valve Stem, Seat, Spacer, Cap, Spring | 13172, 12626, 13167, 13165, 11973 | The brine valve that opens during brine draw and fill |
| Washer, Flow Control, .50 gpm (BLFC) | 12095 (retainer 13245, adapter 13244) | Sets the brine tank refill rate; Pentair sells BLFC kits 60022-12 (0.125 gpm), 60022-25 (0.25), 60022-50 (0.50) and 60022-100 (1.0 gpm) |
| Washer Flow, 2.4 gpm (DLFC) | 12088 (retainer 13173) | Sets the backwash and rinse rate to drain; Pentair warns to leave at least 6 inches between the DLFC and any solder joint |
| Disperser, Air, 5600 | 13497 | The air disperser at the drain |
The pistons differ by application, not by head. The 5600 manual describes the “standard piston (white end plug) or filter piston (black end plug)” and a “low water piston (gray end plug)” that changes the cycle times, so a replacement piston is chosen by the color of the end plug on the old one. Pentair’s 5600SXT manual also lists the 2300 and 2310 safety brine valves for the brine tank.
I send an occasional note when a new guide goes up — repairs worth doing yourself, and the parts that actually last. No spam, no course funnel; written by a licensed Georgia plumber.
What Is Different
- The powerhead. The SXT manual has its own “VALVE POWERHEAD ASSEMBLY” and a separate “MODEL 5600 CONTROL VALVE DRIVE ASSEMBLY” exists in the 5600 manual. Timer parts, motors and the circuit board are listed under separate assemblies in the two manuals.
- The meter. The SXT uses an electronic turbine or paddle meter with a cable: the manual lists the “3/4″ Turbine, w/Clips & Screws” (60626), the “Meter Assy, 3/4” Dual Port, SLP” (19797), the flow straightener (14613) and the “Meter Cable Assy, Turbine/SXT” (19121-01). The mechanical 5600’s metered version has its own meter parts in the 5600 manual; the SXT meter and cable are not those parts.
- Programming. The SXT is set through its programming mode with the codes above; the mechanical timer is set with the skipper wheel, and its salt setting is a mechanical dial the job sheet calls “Salt Setting per Regeneration.”
Ordering the Right Part
- Write down the tank size. Both manuals’ job sheets start with “Mineral Tank Size” and diameter, because the injector follows the tank, not the head.
- Note the head. Dial and skipper wheel, or SXT display. Body parts are shared; head parts are not.
- Check the injector color. White #1 for a 9- or 10-inch tank, red #0 for 8-inch, blue #2 for 12-inch, per Pentair’s list.
- Match the piston end plug color (white, black or gray) if you are replacing the piston.
- Use only PTFE tape on the drain and brine fittings. Pentair’s SXT manual says “PTFE plumbing tape is the only sealant to be used” on the fittings it names, and the 5600 manual says “Plumber tape is the only sealant to be used on the drain” fitting.
FAQ
What is the difference between a Fleck 5600 and 5600SXT?
The head. A Fleck 5600 has a mechanical dial timer with a skipper wheel and a manual regeneration knob; the 5600SXT has an electronic head with a display, an Extra Cycle button, meter-immediate and meter-delayed modes, and an 8-hour power backup. Both use the same 5600 valve body.
Are Fleck 5600 and 5600SXT parts interchangeable?
Body parts are shared in principle: the SXT manual lists the valve body, injector, injector screen, brine valve, BLFC and DLFC washers and the safety brine valve, and the 5600 manual has its own valve assemblies section to confirm the number against before ordering for a mechanical head. The powerhead, timer or circuit board, motor and meter are specific to each head.
Which injector does a Fleck 5600 use?
Pentair sizes the injector nozzle and throat to the tank diameter: #000 brown for 6-inch, #00 violet for 7-inch, #0 red for 8-inch, #1 white for 9- and 10-inch, #2 blue for 12-inch, #3 yellow for 13-inch and #4 green for 14-inch tanks.
How do I start a manual regeneration on a Fleck 5600SXT?
Pentair says to hold the Extra Cycle button for five seconds. On the mechanical 5600, turn the manual regeneration knob slowly clockwise to the first regeneration step and let the motor stop before going on.
Does a Fleck 5600SXT keep its settings when the power goes out?
Pentair says the SXT has a power backup that keeps time and the passage of days for at least 8 hours, goes into a power-saving mode, does not monitor water usage during the outage, and stores the volume remaining.
Why Trust Plumbing Picks
Plumbing Picks is written by a licensed Georgia journeyman plumber. Every part number, model list, size, setting and fit on this page comes from the manufacturer pages and documents listed below, which we opened and read; nothing here comes from hands-on testing. Nobody pays to be included here. More on who writes this and how we pick.
Sources
- Pentair: Fleck 5600SXT Downflow Service Manual (42684)
- Pentair: Fleck 5600 Service Manual (40106)
- Pentair: 5600SXT Series Softener (system sizes)
Bottom Line
Look at the head: knob and skipper wheel means a 5600, a display means an SXT. Order body parts by the tank size and the injector color, head parts by the head, and the piston by its end plug color.