Fleck 5600 SXT Review – Best Fleck Water Softener System for the Whole House

by Curtis Grossi | Last Updated: March 18, 2024

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The Fleck 5600SXT Water Softener is a whole house ion exchange hard water softener system with digital controls and readout that makes it easy to monitor the state of your household water. Fleck water softener will remove the calcium and magnesium that cause hard water in your pipes and the build-up of scale in your appliances, leaving you with soft water that improves soap efficiency and gives you a more enjoyable washing experience.

Many regions have high lime content in their household water, whether it is well water or city water. This comes about either because of the ground conditions that the water is drawn from, or as a result of the city’s water treatment process.

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The programmable controls have a memory backup that lasts up to 48 hours and the brine tank has a safety float system.
The softener’s extra-long life resin lasts up to seven years, with a 10-year warranty on the tank, and a 5-year warranty on the control valve. It is easy to install for someone with basic plumbing skills and has two built-in overfill/overflow safety measures.

The system has a programmable digital meter that measures water use and it will automatically regenerate the system when the water treatment limit is reached, or every two weeks if less water is used.
Overall, the Fleck 5600SXT is a high quality, efficient and long-lasting water softener that will serve you faithfully for many years.

Who is Fleck

Fleck is a tried and trusted name in water treatment and originated from LW Fleckenstein, who patented the ‘Fleck Closure’ valve, better known as the ‘Fleckenstein valve’ in 1955. The Fleck valves are now manufactured by Pentair Water, who can provide technical support.
Fleck Systems, which sells Fleck water softeners and parts, including replacement valves and backwashing filters, is owned by US Water Systems and provides sales support.

Important Features

The Fleck Water Softener has a number of features that make it one of the most versatile and convenient water softeners in the market.

1. Compact Turbine-Electronic Meter

This provides more accurate and flexible measurement of water flow than a mechanical flow meter and it has less moving parts so less potential for breakage.

2. Solid-State Digital Programmable Control offering Four Modes of Operation

This feature offers four modes of operation according to what is most convenient for the user:

3. Remaining Water Volume Monitor

The digital display will indicate how many gallons of water remain to be treated before salt must be added to the brine tank.

4. Memory Backup

In the event of a power failure, or the power supply being accidentally un-plugged, the programmable display will store the remaining water volume, the date and time, and the operational mode settings for over 48 hours, meaning you won’t have to reset it when power is restored within that time.

5. LCD Display

The digital controls have a backlit LCD screen that is easy to read at any time of day, and easy to use touchpad buttons.

6. Double Backwash

The regeneration cycle provides a double-backwash (one slow and one rapid backwash) to improve the efficiency of the process.

7. Safety Float System

The safety float in the brine tank prevents over-filling and the tank has an overflow outlet that can be linked to the backwash drain.

Water Capacity, Pressure, and Temperature Range

The 5600STX has a water capacity of 20GPM (1.26l/s or 75.71l/min) at a hydrostatic pressure of 300psi (20.68bar) and a maximum working water pressure of 125psi (8.6bar).
A minimum water pressure of 20psi (1.4bar) is required for the regeneration valve to operate correctly.

The water softener should be installed in its own cabinet in the house, or it can be placed in the garage. If the water softener is installed outdoors, it should be screened from sunlight to avoid UV damage and must not be exposed to freezing temperatures of less than 34°F (1°C).
The water softener has a maximum operating temperature of 110°F (43°C) and must be installed before any water heating device.

Water and Salt Consumption

The regeneration cycle of the 5600STX discharges about 80 to 100 gallons of water to drain during the regeneration cycle.
The unit will consume 24lb (10.9 kg) of salt for every 48,000 grains of hardness treated, or approximately a 50lb (22.7 kg) bag of salt per month for a family of four, depending on the level of water hardness.

The capacity of the system (48,000 grains) divided by the hardness of the water will indicate the volume of water in gallons that can be treated between regeneration cycles.
The purest level of salt available should be used, solar or purified extra coarse salt, but not granulated or mineral or rock salt.

Fleck 5600SXT Manual

Here you can find a direct link for Fleck5600SXT manual (PDF version) where you can find the detailed instruction needed for installation picture by picture.

Power Rating Consumption

Fleck 5600 is rated at 8.4VA and runs on 110V-120V 50-60Hz with its own power supply rated at 15W reducing the voltage to 24V.
It can be purchased for use with other voltages.

Size, Dimensions and Shipping Weight


  • Digital read-out showing remaining volume of water to be treated
  • Programmable with automatic regeneration cycles (with a maximum of 14 days)
  • Memory backup for programmed entries
  • Flow meter rather than timer for more accurate regeneration cycles
  • Large capacity at 48,000 grains
  • By-pass valve for convenience
  • 5-year warranty on valve, 10-year warranty on tank


  • Difficult to understand installation manual
  • Does not filter water
  • Relatively large size
  • No low salt warning light

Where to Buy Fleck 5600sxt

The Fleck 5600 water softener is obtainable in the US$550 to US$650 range. The easiest way to get one from the comfort of your home is order it at Amazon.

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Fleck 5600SXT Installation (video)


The Fleck 5600SXT 48000 has a 5-year warranty on the control valve and parts, and a 10-year warranty on the double-skin tank. The length of the warranties is an indication of the level of confidence the manufacturers have in the quality of their products.


The Fleck 5600SXT 48,000 Grain Water Softener has received overwhelmingly positive customer reviews on Amazon. The only complaints related to the difficulty in inserting the resin beads (some suppliers pre-load them) and the lack of detailed installation and setup instructions.

So, if you’re not experienced with plumbing installations, it would be advisable to have it installed and set up by a professional, as it will also require additional fittings that are not shipped with the system.
There were also some complaints about the nylon bypass valve supplied with the system, and several people had replaced it with a metal bypass valve.


If you have a problem with hard water and want a convenient, easy to use and reliable water softeners, the Fleck water softener is what you are looking for.
With its programmable regeneration cycle and informative backlit LCD readout, you’ll always know where you stand with your water quality.

To be safe, have it professionally installed, use a metal bypass valve, and it will give you many years of dependable service.

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Curtis is the founder and owner of softeningwater.com. He is the lead guy concerning all the water-softening accessories in this site's guides and reviews. If he is not writing a reviews, guides or any other useful tips, you will find him testing them to find out their suitability. He is passionate about softening water. You will find him extremely helpful and always willing to educate the general populace all there is concerning water and its effects on their health and appliances.