Why is my Fleck 5600SXT not drawing brine?

Force a regeneration and watch the brine tank. Hold the Extra Cycle button for five seconds to start one. It begins at backwash. Press Extra Cycle once to move to the next step, brine draw and slow rinse. Pentair's start-up instructions say to make sure the unit is drawing water from the brine tank at this step, and that the step may need to be repeated.

Lift the brine tank lid and watch the water level. It should drop as the valve pulls brine out. If the level doesn't move, brine draw has failed. Give it a few minutes before you decide, since the draw step is timed. If you want the full set of button presses, see how to manually regenerate a Fleck 5600SXT.

A second sign is what the tank looks like between cycles. If salt use has stopped and the tank level never goes down, the unit hasn't been pulling brine for a while.

The manual's troubleshooting table gives six causes for "softener fails to draw brine." Here they are with what each one means:

1. 1Plugged drain line flow control. This small fitting on the drain line sets the flow during regeneration, and the injector needs that flow to make suction. Clean it.
2. 2Plugged injector. The injector is the venturi that creates the suction that pulls brine. Clean it.
3. 3Plugged injector screen. The screen keeps grit out of the injector. Clean it.
4. 4Line pressure is too low. The manual says to increase line pressure to 20 psi, and elsewhere says a minimum of 20 psi is required for the valve to operate effectively. A softener on a home with poor pressure can't pull brine. See what causes low water pressure across the whole house.
5. 5Internal control leak. The fix is new seals, spacers and the piston assembly.
6. 6Service adapter did not cycle. Check the drive motor and switches.

The same table lists a neighbor of this problem. If there is too much water in the brine tank, the causes include a plugged drain line flow control, a plugged injector system, a timer that isn't cycling, foreign material in the brine valve and foreign material in the brine line flow control. Water that keeps rising in the salt tank and brine that never gets pulled out often come from the same clogged parts.

### Could the drain line or the install be starving the injector?

Yes, and it's worth a look if the softener was recently installed or moved. The injector works off the flow of water to the drain, so anything that chokes that flow chokes the suction. Pentair's installation rules say the residential drain line should be at least 1/2 inch, and that a backwash flow over 7 gpm or a drain run longer than 20 feet needs a 3/4 inch line. Look for kinks, a line that climbs high before it drains, and any partly crushed tubing. The drain must also end in an air gap of twice the pipe diameter, with a 1 inch minimum, so drain water can't back up into the system.

Plumbing upstream can matter too. Pentair says the existing pipes should be free of lime and iron buildup, that heavily built-up piping should be replaced, and that iron-clogged piping calls for a separate iron filter ahead of the softener. Grit shaken loose by recent plumbing work is a classic way to plug a screen. The manual lists "inlet of control plugged due to foreign material broken loose from pipes by recent work" as a cause of low flow through the softener.

### What about the salt itself?

Check the tank before you take anything apart. A crust of salt that spans the tank over an empty pocket of water is called a salt bridge, and it stops any softener from making brine. Kinetico's owner's manual describes the same problem on its systems: humidity and low salt use contribute, and you can break a bridge up by carefully poking the salt with a stick or broom handle. Kinetico also suggests keeping the brine tank filled only to about the halfway point.

Pentair adds one rule for every Fleck owner: do not use granulated or rock salt in the brine tank. Fine grit and dirt from the wrong salt is a common way an injector screen ends up blocked in the first place.

Cleaning is a reasonable homeowner job if you take it slowly. Pentair warns that the system must be depressurized before you remove any connections. In practice that means:

1. 1Put the softener on bypass, or shut off the water to it.
2. 2Unplug the control.
3. 3Open a faucet nearby to relieve pressure.
4. 4Remove the injector cap and screen, then take out the nozzle and throat and clean them.
5. 5Reassemble in the same order and make sure the parts seat squarely.

Pentair's own instruction for the O-rings is to use only silicone lubricant, so skip petroleum jelly.

Pentair's parts list shows that the injector nozzle and throat are numbered and color coded by tank size, from a #000 (brown) for a 6 inch tank up to a #4 (green) for a 14 inch tank. If you buy a replacement, match it to your tank. The wrong size pulls too little brine or too much, and you'll be back where you started.

After you put everything together, run a manual regeneration and watch the brine level drop. Repeat the step if needed, as the manual suggests.

Give it a day or two. Pentair lists "hot water tank hardness" among the reasons for hard water after a softener problem, and the fix is repeated flushing of the hot water tank. Kinetico's manual says the same: if the hot water tank refilled with hard water, it can take several days to empty and for the water to feel soft again. The tank has to be drawn down and refilled with soft water before every tap tests soft.

A hardness test strip is the honest way to check. Test a cold tap on the soft side of the plumbing, then a hot one a day later. Also confirm the bypass valve isn't open. The manual lists an open bypass as a cause of hard water, and it happens more than you'd think after a service visit.

If you've cleaned the drain line flow control, the injector and the screen, confirmed 20 psi or more, and the softener still won't draw, the problem is inside the valve. Seals, spacers and pistons are a bigger job, and mistakes during reassembly can leak or send resin down the drain. It's also worth bringing in a pro if the unit throws an error code, in which case check what the Fleck 5600SXT error codes mean first.

HQ Plumbing & Air gives free estimates and upfront pricing on water softener service. For the wider checklist on a softener that has stopped working, see why a water softener stops working.