Fleck 5600SXT Water Softener: Complete Owner's Guide

The Fleck 5600SXT manual is a free PDF from Pentair: the Fleck 5600SXT Downflow Service Manual. Our softeners on this valve arrive without a printed manual, and people call me with a new softener and no paperwork. This is the owner's guide to the valve on the softeners we sell: what to set, what to leave alone, what the codes mean, what your plumber connects and which parts wear out.

Caller "I just had a delivery of a unit here, and it did not come with any programming instructions."

Aidan "The only thing you program on that is the time of day, the capacity, which is either 48 or 64, depending upon which size you purchased, and your hardness setting, which defaults to 20."

A caller this July, with a new neutralizer and a 5600SXT softener. The rest of this page is the long version of that answer.

The free Fleck 5600SXT manuals

The manual for the Fleck 5600SXT is Pentair's Fleck 5600SXT Downflow Service Manual, a free PDF on pentair.com. Pentair publishes three documents for this valve, and each one answers a different question.

A buyer of our 48,000 grain softener wrote in May 2026: "The product came with no instructions or operating manual. However, I was able to go online and get manuals from another supplier without a problem." The three manuals above come straight from Pentair.

Which 5600 valve do you have?

Fleck has sold the 5600 valve with more than one controller, and the manual has to match yours.

• 5600SXT: a digital display and three buttons, Extra Cycle, Up and Down. Every softener we sell on this valve has it. The manuals above are for this one.
• Mechanical 5600: no display. It has a 24-hour gear with a red button you push to set the time, and a knob you turn clockwise to start a regeneration. The timed version has a skipper wheel where "each tab is one day"; the metered version has a wheel set in gallons. Its manual is Pentair's Fleck 5600 Service Manual.
• NXT2: Pentair's controller with a bright screen and touch buttons. Pentair's NXT2 manual lists it for the 2510 and larger valves, not the 5600.

If you are still choosing a valve, my honest Fleck 5600SXT review covers whether it is the right one for you.

Programming Guide

On the Fleck 5600SXT softeners we sell, you set the time of day, the capacity and the hardness, and you leave the rest alone. The cycle times, the regeneration time and the day override are already set. On the phone I put it this way: "You don't change anything but the hardness and the capacity."

Step-by-Step Programming

To open the settings on the 5600SXT, press and hold the Up and Down buttons together for five seconds while the valve is in service. Use Up and Down to change a value and the Extra Cycle button to move to the next setting. If you do not press anything for 60 seconds, the valve exits and discards the changes.

That opens the owner's menu, and it is where you change the hardness later. It shows these settings in this order:

The menu will not open while the clock reads 12:01 PM, because that time opens Master Programming instead.

Setting up a new 5600SXT

The capacity is not in the owner's menu. It is in Master Programming, the installer's menu, along with the hardness. Pentair's manual tells you to call your water dealer before you go in there; that dealer is me. On a new softener, this is the whole setup:

1. Set the clock to 12:01 PM

   Hold Up or Down until TD shows, then use Up and Down to set the time to 12:01 PM. Press Extra Cycle.

2. Open Master Programming

   Hold Up and Down together until the display shows DF. That is the first Master screen.

3. Set C to your softener's size

   Press Extra Cycle, without changing anything, until the display shows C. Set it to the size you bought, in grains: 32,000, 48,000, 64,000 or 80,000.

4. Set H to your hardness

   Press Extra Cycle once to reach H, and set your hardness in grains per gallon. The next section tells you what number to use.

5. Set the real time last

   Keep pressing Extra Cycle through every other screen without changing it. At the last one the valve saves and goes back to service. Then hold Up or Down and set the clock to the real time of day.

Don't stop partway. If you leave the valve sitting in Master Programming without pressing a button, it throws out your changes, and you start over.

What to set the hardness to

Set H to the hardness on your water test, in grains per gallon. If an acid neutralizer, or an iron filter with a calcium-based media, sits ahead of the softener, add 4: that media adds a little hardness to the water. As I told a caller in August, "Whatever the hardness is, raw hardness is, add to four." So 6 grains raw water gets set at 10. If you have a neutralizer and no hardness number yet, set 15 until you test; that is what I tell callers in that spot.

No number yet? The certified well water test reports hardness in grains per gallon. How to test water hardness covers the other ways to get it.

Setting up a new Fleck 5600SXT

Text me your hardness for the setting

Send me your softener's size, your hardness and what is ahead of the softener. I'll text back the two numbers to put in.

Text Aidan443-277-2204 Call800-460-5810Aidan

Call 800-460-5810 or text Aidan at 443-277-2204. 8 AM to 5 PM Eastern, seven days a week.

Settings Got Reset?

The 5600SXT keeps its settings through a power outage, so a reset is rarely the problem. Pentair's manual has two resets, a soft reset and a master reset, and either one can wipe out the capacity and hardness. Call me before you use one. If that happens, redo the five steps above, or call me and I'll walk you through it.

What the buttons do

In service, the display alternates between the time of day and how much is left before the next regeneration: gallons on a metered softener like ours. A small flow light flashes whenever water is running in the house.

A regeneration is the softener cleaning the resin and recharging it with salt water. During one, the display shows a two-letter code for each step: BW is backwash, BD is brine draw and slow rinse, RR is rapid rinse, and BF is brine refill. The whole thing takes about an hour and a half. My guide to water softener regeneration explains what happens in each step and how often it should run.

Fleck 5600SXT error codes

A Fleck 5600SXT shows an error code in place of the normal display, and the number tells you which fault it found.

If the softener shows no code but the water is hard, the salt is not going down, or there is too much water in the salt tank, water softener troubleshooting goes through the causes in order.

After a power outage

The 5600SXT keeps every setting through an outage, and the clock keeps time for at least 8 hours. When the power comes back, the time of day flashes to tell you it went out: press any button and check the time. If it was in the middle of a regeneration, it picks up where it stopped. A regeneration that came due during the outage runs at the next 2 AM.

The bypass valve

The bypass on our Fleck softeners has one handle: turn it so the arrow points to BY PASS to send water around the softener, and to SERVICE for soft water. It comes installed on the valve.

Put it in bypass before anyone works on the valve, and the house keeps its water while the softener is out of the loop. Turn the handle back to SERVICE slowly, so the softener fills gently.

If the bypass starts to leak around the handle, the fix is the Fleck bypass replacement seal ($45), not a new bypass.

What your plumber connects

We recommend installation by a licensed plumber, and I support your plumber by phone at 800-460-5810. A licensed plumber typically completes the install in 2 to 3 hours. What ships: the mineral tank (empty), the control valve with the bypass valve pre-installed, the brine tank, and the resin in separate bags. The resin is loaded into the tank at install. Drain tubing is not included; it is 1/2 inch flexible tubing from any hardware store.

• Water in and out. The incoming water goes to the inlet side of the bypass. Pentair warns that old plumbing is sometimes reversed, so check the direction before the pipes are connected. Pentair also says to use only 100% silicone grease on the O-rings, never petroleum grease, and to let soldered pipe cool before it goes near the bypass.
• Connect the drain line. Attach the drain line to the drain fitting on the valve head. Run it to your floor drain or utility sink. Use 1/2 inch tubing, clamped to the fitting, and 3/4 inch if the run is over 20 feet. The drain line can rise up to 6 feet if the run is 15 feet or less and you have at least 40 psi. Leave an air gap at the end of at least 1 inch, and never push the line down into a drain or trap.
• Tie down the end of the drain line. It moves when the softener backwashes. People call me after stuffing it loose in a standpipe and ask, "Why is there water flying everywhere?"
• The brine line. It runs from the salt tank to the valve. Push the tube all the way into its fitting; as I tell people, sometimes it sticks a little and you have to turn it left and right as you push.
• The overflow (optional). The fitting on the side of the salt tank takes its own 1/2 inch line to the drain, lower than the fitting. It never tees into the valve's drain line.
• Power. The valve runs on the plug-in transformer that comes with it. Use an outlet that is grounded and always on, not one on a switch.
• Pressure and temperature. The valve works on 20 to 125 psi and cold water no hotter than 100°F. Keep it somewhere dry that never freezes.

Pentair's start-up runs in this order: water added to the salt tank (Pentair says about an inch over the grid plate) and no salt yet, the bypass set to bypass, then the handle turned slowly to service with a cold faucet open to push the air out, then the valve plugged in and programmed. Salt goes in at the end. Pentair's start-up also has the installer step the valve through its regeneration positions. That is the time to watch the drain line, "to make sure your backwash lines are secure."

Salt tank care

Use plain salt pellets made for softeners, and keep the salt above the water in the salt tank. Pentair says no rock salt or granulated salt, and its system manual says the tank works best with the salt below half full; filled higher, the pellets can stick together into a crust, a salt bridge, over the water. Empty and clean the salt tank every three years.

The 5600SXT has no salt setting. The salt per regeneration comes from how long the valve refills the salt tank. On the softeners we sell it is about 5 pounds on the 32,000 grain, 7 on the 48,000, 10 on the 64,000 and 12 on the 80,000. If the salt has stopped going down, see salt bridges and the other causes.

In this video I go through what a softener on the 5600SXT needs from you: how often to add salt, which salt to buy and how the regeneration works.

Parts that wear out

On a 5600SXT, the parts that wear are the seals and spacers and the piston that slides inside them. As I tell people, "ten or fifteen years down the road, you may have to replace some pistons or a control board, which is fairly simple to do." These are the parts we sell for it, at today's prices:

	Part	What it fixes	Price
	Fleck 5600 Valve Seal & Spacer Kit	Hard water coming through, or water that keeps running to the drain	$55
	Fleck 5600 Piston Assembly Standard	A worn piston (the rod that slides inside the seals). Order the standard one.	$75
	Fleck 5600 Valve Repair Kit	A full rebuild: seals and spacers, piston, brine valve, drive motor, injector screen and O-rings	$185
	Fleck Injector/Drain Assembly (2.4 DLFC / .50 BLFC)	A softener that won't pull salt water even after you clean the injector	$180
	Fleck 5600SXT Water Softener Control Valve	A whole new valve head, when the old one is worn out	$545

The resin in the tank is a separate job: softener resin covers how long it lasts and how to rebed a water softener when it is worn out.

What buyers wrote about programming it

These are verified purchases of Fleck SXT valves from us, from 2020 to this year.

Frequently asked questions