Guide

How to Program a Fleck 5600SXT

The Fleck 5600SXT is the most common residential softener valve in North America: a digital, metered, downflow, single-tank control that stores its whole configuration in Master Programming. Once it is set correctly it runs untouched for years. This guide walks you through reaching the programming menu on the 5600SXT specifically, then through every parameter in the order the valve presents them, with the values that suit a typical single-family home.

Set the time of day first

Before you touch anything else, set the clock. From the normal display, a quick tap of the Up (▲) or Down (▼) arrow lets you set the current time — no long hold is needed for this. The time of day matters because the 5600SXT is a meter-delayed valve: when your softened-water reserve is used up, it waits until the programmed regeneration time (usually 2 AM) to actually regenerate. If the clock is wrong, the valve will regenerate at the wrong hour — often in the middle of your morning shower, when you least want hard water at the taps.

Entering Master Programming

Master Programming is where the real settings live. To open it:

Make sure no water is running and the valve is not mid-regeneration. Programming a valve while it is cycling can leave it in an odd state.
Press and hold the Up (▲) and Down (▼) arrows together for about five seconds, until the display changes to the first parameter. That combination is the only way in — a short press just adjusts the clock.
Use the Extra Cycle button — the circular-arrow / regen key — to advance from one parameter to the next.
Use the Up/Down arrows to change whichever value is flashing on screen.
When you have set the last parameter, press Extra Cycle once more to step past it. That saves your changes and returns the valve to the normal time display.

If the arrows will not change a value, the keypad is probably locked. The 5600SXT has a keypad lockout to stop accidental changes; the unlock button combination is printed in the owner's manual for your firmware. Unlock it, then re-enter Master Programming.

Write down the current values first

Before you change a single setting, step through the menu once and note every existing value on paper. If a new setting turns out wrong, you can roll straight back instead of guessing. Procedures and the exact parameter list vary slightly between firmware revisions and sub-models, so keep the configuration sheet that shipped with your valve alongside these notes.

Working through each parameter

The 5600SXT presents its settings as short codes. Here is what each one means and the value a typical residential, single-tank system wants. The three that depend on your specific water and household — capacity, hardness, and reserve — are the ones worth getting exactly right.

DF (Display Format): set to Gal for gallons on a U.S. system. The alternative shows litres or cubic metres.
VT (Valve Type): dF1b, downflow with a single backwash — the standard for residential softeners.
CT (Control Type): Fd, Meter Delayed. The valve tracks how much water you have used and regenerates at the set time once the reserve is exhausted.
NT (Number of Tanks): 1 for a single-tank softener.
C (Unit Capacity): the resin's grain capacity in kilograins. Match it to your resin volume: roughly 24 for 0.75 cu ft, 32 for 1.0 cu ft, 48 for 1.5 cu ft, and 64 for 2.0 cu ft. Setting this too high tells the valve it can treat more water than it really can, and hardness slips through before the next regeneration.
H (Hardness): your compensated hardness in grains per gallon. Start with your measured hardness and add 5 GPG for every 1 PPM of dissolved iron in the water. Getting this number right is the whole point of a proper water test.
RS (Reserve Selection): rc for a fixed reserve capacity in gallons, which is the most predictable choice. The alternative, sf, uses a safety-factor percentage instead.
RC (Reserve Capacity): gallons held back before regeneration, roughly three times your average daily use. This buffer means a busy day will not run you out of soft water before the scheduled 2 AM regen.
SF (Safety Factor): defaults to 15%. It is only used if you chose sf at Reserve Selection; with rc you can leave it alone.
DO (Days Override): a maximum of 3 to 14 days between regenerations, regardless of how little water you use. Even a lightly used softener should recharge periodically to keep the resin bed fresh and prevent bacterial growth.
RT (Regeneration Time): 2:00, i.e. 2 AM — a low-usage hour when no one needs water and the drain line is free.
BW (Backwash): 10 minutes, standard for tanks up to about 2 cu ft. This reverse flow lifts the bed and flushes out trapped sediment.
BD (Brine Draw + Slow Rinse): 60 minutes. The brine draws in during roughly the first 20 minutes; the remainder is a slow rinse that carries the salt through the resin and does the actual recharging.
RR (Rapid Rinse): 10 minutes, a fast rinse that packs the bed and flushes the last of the brine before the valve returns to service.
BF (Brine Fill): about 10 minutes per cu ft of resin. This measures water into the brine tank to dissolve salt for the next regeneration.
FM (Flow Meter): t0.7 for the 3/4" turbine meter used on most residential valves. Match this to your actual meter size or the gallon tracking will be off.

Recommended residential values at a glance

The values for capacity, hardness, and reserve come from your own water numbers and household size. The calculator generates a personalized version of this exact table from your hardness, iron, resin size, and daily water use.

Code	Setting	Typical	What it does
DF	Display Format	Gal	Gallons for U.S. systems; the alternative shows litres or cubic metres.
VT	Valve Type	dF1b	Downflow, single backwash — the standard residential configuration.
CT	Control Type	Fd	Meter Delayed: regenerates at the set time after the reserve is used up.
NT	Number of Tanks	1	One for a standard single-tank softener.
C	Unit Capacity	24–64	Kilograins matched to resin volume: ~24 for 0.75, 32 for 1.0, 48 for 1.5, 64 for 2.0 cu ft.
H	Hardness	Your GPG	Compensated hardness in grains per gallon; add 5 GPG per 1 PPM of dissolved iron.
RS	Reserve Selection	rc	Fixed reserve capacity in gallons; the alternative sf uses a safety-factor percentage.
RC	Reserve Capacity	~3× daily use	Gallons held back so you do not run dry before a scheduled regeneration.
SF	Safety Factor	15%	Factory default; only used when Reserve Selection is set to sf.
DO	Days Override	3–14	Maximum days between regenerations regardless of usage — keeps the bed fresh.
RT	Regeneration Time	2:00	A low-usage hour, so soft water is restored well before morning.
BW	Backwash	10 min	Lifts and rinses the resin bed; standard for tanks up to ~2 cu ft.
BD	Brine Draw + Slow Rinse	60 min	Brine draws in ~20 min; the rest is a slow rinse that recharges the resin.
RR	Rapid Rinse	10 min	A fast rinse that flushes the last of the brine before service.
BF	Brine Fill	~10 min/cu ft	Refills the brine tank to dissolve salt for the next cycle.
FM	Flow Meter	t0.7	3/4" turbine meter, the standard residential size; match to your meter.

Test with one manual regeneration

Programming alone does not prove the plumbing works. Once you have saved your settings, trigger a single manual regeneration by holding the Extra Cycle button until the valve steps into the first cycle. Watch it through: the water level in the brine tank should visibly draw down during the brine-draw stage and then refill during brine fill. If the brine tank draws down and refills, you have confirmed the injector, the drain line, and the brine valve all work with your new settings. If the level never drops, suspect a clogged injector or a salt bridge before you blame the programming.

Related guides

Softener calculator — turn your hardness, iron, and resin size into the exact capacity, hardness, and reserve values to enter above.
General programming guide — how to reach the settings menu on other models, including Clack WS1, GE, Whirlpool, and mechanical Fleck valves.
Maintenance schedule and troubleshooting guide — keeping the softener running, and what to check if something is wrong after programming.