Fleck 5600 SXT Program and Reset Procedure

Why this matters

The Fleck 5600 SXT (Pentair P/N 5600SXTDF1Y) is the most-installed mid-tier residential metered softener control valve in North America, fronting tanks from 24,000 to 80,000 grain nameplate capacity. It is also the most commonly mis-programmed valve in the field. Dealers preset the SXT at the shop against a guessed hardness, the house it lands in has different water, and nobody goes back and re-enters H. The Master Program itself sits in EEPROM and survives a power loss; what does not survive a long outage is the time of day, so a valve that was set to regenerate at 02:00 comes back regenerating in the middle of the morning shower. This guide walks the full Master Program for a typical 1 cubic ft residential softener, plus the two button-combos that get a tech out of a stuck cycle without a full reset.

Confirm the valve and tank size

Read the label on the back of the SXT power board:

• 5600 SXT - 1 inch valve, residential.
• 5600 ECONOMINDER (mechanical, NOT SXT) - different valve, different procedure.
• 5810 SXT - 1.25 inch, larger residential / light commercial.

For tank size, measure the tank diameter and height; the standard residential sizes are:

That column is the marketing nameplate, 32,000 grains per cubic ft, and it is not the number you program. It is the resin's ceiling at a salt dose nobody actually runs. The C value you enter is the usable capacity at the salt dose this valve is set for, which on standard 8 percent crosslink resin is 20,000 to 30,000 grains per cubic ft. Enter the nameplate as C and the valve forecasts capacity the tank does not have, and the customer gets hard water before the regen fires.

Test the customer's water before programming

Programming the SXT correctly requires hardness in grains per gallon. Pull a fresh sample from the inlet (before the softener) and titrate with a Hach hardness test kit or a Hanna total hardness titration kit. Check the kit box says hardness, not alkalinity; the two sit next to each other in every catalog and the model numbers differ by one digit. Common results:

• City water: 5-20 gpg typical, 30+ in hard-water cities.
• Well water: 15-50+ gpg, often with iron.

If iron is present, add 5 gpg to the measured hardness per ppm of iron (the WQA-standard correction). Example: 25 gpg measured hardness with 2 ppm iron = program 35 gpg.

Enter the Master Program

The SXT has two program levels - User and Master. User-level settings (current time, manual regen) can be reached from any state. Master Program is locked behind a button combo.

1. Press the SET CLOCK button.
2. Press and hold the up arrow and down arrow simultaneously for 5 seconds.
3. Display advances to the Master Program first screen (DF for Display Format).

If the display does not advance, the time of day shows zero - cycle power and try again.

Walk every Master Program screen

The SXT walks through these screens in order. Press SET CLOCK to advance.

1. DF (Display Format) - GAL for gallons-based US units. Set to GAL.
2. VT (Valve Type) - For a 5600 SXT softener with downflow brining, set to St1bd.
3. CT (Control Type) - Fd (forecast) for a metered valve with day override. tc (time clock) only for non-metered installs.
4. NT (Number of Tanks) - 1 for a standard single-tank softener.
5. C (Capacity in kilo-grains) - the usable resin capacity at the salt dose you are actually running, not the tank's nameplate. On standard 8 percent crosslink resin, per cubic ft: 6 lb of salt gives about 20, 8 lb about 24, 10 lb about 27, 15 lb about 30. So a 1 cubic ft tank run at 8 lb enters 24, not the 32 on the sticker. Scale by resin volume for larger tanks and check the resin manufacturer's own salt-dose curve (Purolite C100E, Lanxess Lewatit S 1567).
6. H (Hardness in gpg) - the inlet hardness you measured. Example: 35.
7. RC (Reserve Capacity, %) - typically 0 (Fixed Reserve mode) or set the percent reserve for a forecast model. Default 30%.
8. DO (Day Override) - maximum days between regens. Set to 7 for a metered valve - the valve regens on volume OR every 7 days, whichever comes first.
9. RT (Regen Time) - clock time the regen starts. 02:00 is the standard residential setting (low water-use window).
10. BW (Backwash duration, min) - 10 for most residential.
11. BD (Brine Draw / Slow Rinse, min) - 60. This is the most critical timing for salt efficiency.
12. RR (Rapid Rinse, min) - 10.
13. BF (Brine Fill, min) - calculated from the salt dose, not guessed. Brine fill water dissolves about 3 lb of salt per gallon, so an 8 lb dose needs about 2.7 gallons; at a 0.5 gpm refill rate that is about 5.5 minutes. The label inside the brine tank usually shows the GPM rating. A fill that runs long over-salts every regen and can float the brine tank.
14. FM (Flow Meter Type) - the digit in the token is the meter size, so t0.7 is the 3/4 inch turbine that ships on most 5600 SXT softeners and t1.0 is the 1 inch turbine. The 5600 body being a 1 inch valve does not mean the meter on it is 1 inch. Confirm against the meter actually installed; the wrong meter type misreads gallons.

After the last screen, press SET CLOCK once more to exit Master Program. The display returns to current time and the program is saved to EEPROM (survives power loss).

Force a manual regen

Press REGEN once for a delayed regen at the scheduled RT time. Press and hold REGEN for 5 seconds for an immediate regen (the valve advances to Backwash). Use immediate regen to confirm:

• Backwash water visible at the drain (good flow rate, no resin escaping).
• Brine draw pulling brine from the brine tank (drop in brine tank level).
• Rapid rinse clearing residual brine.
• Return to service position.

A full cycle on a 5600 SXT residential softener is about 90 minutes. Do not interrupt power mid-cycle - the valve stalls and you have to walk it manually using the EXTRA CYCLE button.

Cycle reset (when the valve is stuck mid-cycle)

If the valve power-cycled mid-regen and the display shows REGEN with no progression:

1. Press EXTRA CYCLE to advance to the next cycle.
2. Repeat until the valve returns to Service.

If EXTRA CYCLE does not advance, the drive motor or position switch has failed. Replacement parts: 18743 (drive motor), 19381 (camshaft and position switch assembly).

Full factory reset

When the program is corrupted and you want to start clean:

1. Unplug the power transformer.
2. Hold REGEN.
3. Plug the power back in while continuing to hold REGEN.
4. Release after the display lights up and shows the firmware version.

The Master Program reverts to factory defaults. Walk through Master Program from step 1 above to re-enter the install-specific values.

Common programming errors

References

• Pentair Fleck 5600 SXT Service Manual, document FL-SXTMAN Rev 5 (2023)
• NSF/ANSI 44-2023 - Residential Cation Exchange Water Softeners
• NSF/ANSI 372-2023 - Drinking Water System Components - Lead Content
• Purolite C100E Technical Data Sheet, 2024
• Pentair Technical Bulletin TB-FL-2022-06 - SXT Master Program Field Defaults
• WQA Technical Application Bulletin - Softener Salt Dose Optimization (2024)