Fleck 5600SXT: The Honest Review (32 Years of Experience)

I have a Fleck 5600SXT in my own house, a 48,000 grain softener on water that tests 15 grains hard, and after 32 years in this business it is still the valve we always come back to. It is not the newest valve and it is not the one with the most features. It is the one that keeps running, and when a part finally wears out, the parts are easy to get. Ours run $1,495 to $2,495, depending on the size.

This is the honest version of what I tell people who call about it: what each size costs from us, what wears out and what the parts cost, the one mistake that shortens its life, and how it stacks up against the Clack WS1 and the other Fleck valves.

The Honest Verdict

The Fleck 5600SXT is the most reliable residential water softener control valve we have ever used, and the one we recommend to almost every customer.

There are three main valves in the American industry: Clack, Fleck and Autotrol. We've been dealers for different companies over the years, and we've always come back to the Fleck. I call it the blue collar valve. It gets up every day, goes to work, doesn't complain, and gets the job done.

Buy one if you have hard water, on a well or city water, and you want a valve that any plumber or service tech can get parts for. The Fleck is easier to work on than the Clack, and its parts are more readily available.

Skip it, or solve something else first, if:

• Your well has iron. Iron shortens the life of the resin, and I recommend a dedicated iron filter ahead of the softener. See the iron section.
• Someone in the house uses water at every hour. A single-tank softener regenerates overnight. For soft water around the clock, see the twin-tank 9100SXT in the valve comparison.
• You want no salt at all. The 5600SXT regenerates with salt.

What I have in my own house

A 48,000 grain Fleck 5600SXT. My water is 15 grains hard, there are 3 people in the house, and I have the salt set at 6 pounds per regeneration. We use a ton of water, and we only use about one bag of salt every 30 to 45 days.

What each Fleck 5600SXT size costs

Every size uses the same 5600SXT valve, and the bigger sizes hold more resin, so they soften more water before they recharge. The size number is how many grains of hardness it removes before it recharges. All four carry 10% crosslink resin (a tougher grade than the standard 8%), a 5 year warranty on the valve and a 10 year warranty on the mineral tank.

Which one you need depends on the hardness in your water, how many people live in the house, and how many bathrooms can be used at one time. If somebody tells you that you can get away with a 32,000 grain, I would recommend a 48,000 grain. If you don't have a hardness number yet, the certified well water test reports it along with iron and pH.

What ships in the box

• The mineral tank ships empty. The resin comes in separate bags and is loaded into the tank at install.
• The control valve arrives with the bypass valve already installed on it.
• The brine tank, for the salt.
• Drain tubing is not included. The valve needs 1/2 inch flexible tubing to a floor drain, utility sink or standpipe, which any hardware store sells.

We recommend installation by a licensed plumber, and I support your plumber by phone at 800-460-5810. Some buyers wrote that no manual came in the box; Pentair's own Fleck 5600SXT manual is a free PDF.

Not sure which size you need

Text me for the right size

Send your hardness number, how many people live in the house and how many bathrooms you have. I'll tell you which size I would buy.

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

Call 800-460-5810 or text Aidan at 443-277-2204.

Can the Fleck 5600SXT handle iron?

It can handle low levels of iron for a period of time, but iron shortens the life of the softener resin. A lot of people try to take iron out with a softener, and eventually the resin fails. For a well with iron, I recommend a dedicated iron filter ahead of the softener, like our Fleck 2510AIO with Katalox Light. Whether you need both is in Iron Filter vs Water Softener.

What buyers wrote

These are verified purchases from our reviews, newest first, complaints included.

How the 5600SXT compares with other valves

The Clack WS1 is pretty close to the 5600SXT in performance, and the other Fleck valves each fit a different job.

The 5600SXT vs the 5800

The 5800 is a newer valve with some more features on it than the 5600, but it doesn't actually sell that well, and we don't sell it. The 5600SXT is the older, more proven valve. Functionally they are very similar (both are electronic metered demand, single piston, 20 and 21 GPM service flow). The real difference on Pentair's sheets is the backwash: 17 gallons a minute on the 5800, against 7 on the 5600SXT.

There is no Fleck 5900

People call and tell me they saw a Fleck 5900 online. There's no such thing as a Fleck 5900. What they saw is usually spelled F-L-E-X-X, made up to sound like Fleck, because a lot of people try to knock the Fleck valve off. There are valves that come in from overseas that look similar to it, but they are not an actual Fleck.

What wears out on a Fleck 5600SXT

Down the road, maybe 10 or 15 years, the seals and spacers, the piston or the electrical board may need replacing, and we sell each part. It is a very simple valve to work on, and the board is a plug-in part.

How long they last varies. They can last 5 years. They can last 20.

Photo	What you notice	What to check	The part
	Hard water at the tap again	A leak inside the valve. Pentair: replace the seals and spacers and/or the piston.	Seal and spacer kit, $55
	The drain line keeps running and won't stop	A leak inside the control. Pentair: replace the seals and the piston assembly.	Piston, $75, or the repair kit, $185
	Water leaking from the valve body itself	If it leaks from the valve body, that could be a crack in the valve body.	New 5600SXT valve, $545
	An error on the display, or lost settings	Pentair: a control board memory failure. Do a master reset and reprogram it.	The board, a plug-in part

The resets and error codes are in the Fleck 5600SXT Complete Owner's Guide. If your softener is still under warranty from whoever sold it, call them before you buy a board. That stuff is expensive.

The mistake that wears out Fleck valves

The one problem we have is that a lot of people don't put a sediment filter, like a 5 micron cartridge, ahead of their water treatment systems. Dirt and grit get into the valve, and it doesn't matter what brand it is. It starts to wear away at the working mechanisms inside, the pistons and the seals, and it shortens the life of the valve.

We always recommend putting the filter in before the softener to protect the pistons and the seals. On a well, the order is the pressure tank first, then the 5 micron sediment filter, then the softener.

Frequently asked questions