Maintain
Cleaning a Water Softener Injector
Water softener injector cleaning clears the small venturi nozzle, throat and screen that pull brine into the resin tank. A clogged injector stops the softener drawing brine, so the water turns hard and the brine tank fills up.
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Quick answer
- The injector (venturi) uses water flow to suck brine from the brine tank.
- Clogs show as hard water, a full brine tank and salt that never drops.
- Bypass, relieve pressure and unplug before opening the injector body.
- Clean the nozzle, throat and screen; fit new O-rings with silicone lubricant.
- Look over the injector and brine line yearly, per Quality Water Treatment.
What the injector does
During regeneration the softener has to pull brine out of the brine tank and push it through the resin. It does that with an injector, also called a venturi. Water rushes through a tiny nozzle and into a throat, and the jet creates suction that draws brine up the brine line. A fine screen in front of the nozzle catches grit.
Because the passages are so small, a little sediment, salt residue or iron can block them. When that happens the valve still runs its cycle on schedule, but no brine reaches the resin, so the beads never recharge. The injector sits in the control valve body, usually under a small cap held by two screws on Fleck valves. For a tour of the other valve parts, see water softener parts explained.
Signs of a clog
The Fleck 5600SXT service manual lists a plugged injector or injector screen as a cause of each of these:
- Hard water even though there is salt in the tank and the settings are right.
- Excess water in the brine tank, because the refill goes in but nothing is drawn out. See brine tank full of water.
- Softener fails to draw brine. The manual also lists a plugged drain line flow control, line pressure below 20 psi and internal leaks as causes.
Quality Water Treatment adds that a salt level that never changes suggests the softener is failing, so rule out a salt bridge first. If the salt is not going down, our guide to a softener not using salt walks through the full list.
SoftPro gives a brine-draw check for the Fleck 5600SXT. Press and hold Extra Cycle for roughly 5 seconds until BW (backwash) appears, press it once more to move to BD (brine draw), then pull the brine line off where it meets the float. Put a finger over the end, or dip it in water, to check for pull. No suction points to the injector, the drain line or the brine valve.
Cleaning steps
These steps follow the Fleck 5600SXT service manual. Other valves have different layouts, so check your own manual for the injector location.
- Bypass the softener. Turn the bypass to bypass so the house keeps water. The bypass valve guide shows each handle type.
- Relieve the pressure. Step the control into Backwash for a moment, then return it to In Service.
- Unplug the valve.
- Disconnect the lines. Take the brine tube and drain line off the injector body.
- Remove the injector body. Undo the two screws that hold it.
- Take out the cap and screen. Then unscrew the nozzle and throat.
- Clean each part. SoftPro suggests soaking the nozzle, throat and screen in white vinegar or a descaler, blowing them out with compressed air and clearing the passages with a nylon brush. For the screen, Quality Water Treatment uses a fine needle plus a weak vinegar solution.
- Inspect. Quality Water Treatment says to replace the injector if it cannot be cleaned.
Vinegar is for parts you have taken off the valve only. Quality Water Treatment says not to put vinegar into the brine tank.
While the valve is open, it is a good time to think about the rest of its service. Quality Water Treatment advises a yearly service of the control valve's piston, seals and spacers; for its Fleck 5600SXT systems the kit is part 60010307.
Reassembly and testing
- Refit with new O-rings. The Fleck manual says to put the parts back with new O-rings lubricated with silicone. Pentair's manual allows only pure (100%) silicone lubricant on the O-rings; petroleum grease is out.
- Reconnect the brine tube and drain line.
- Return the bypass to service. Open it slowly.
- Check for leaks. The Fleck manual says to look over every seal area, and to have the control in Backwash when you inspect the drain seal.
- Plug in and set the time. Then cycle the valve manually through its steps. On a 5600SXT, holding Extra Cycle for 5 seconds starts a regeneration, and pressing it again moves to the next step. The Fleck 5600SXT programming guide has the button details.
- Confirm the brine draw. Repeat the suction test above during BD to make sure the brine line now pulls.
If the brine tank still fills up or the water stays hard after cleaning, Quality Water Treatment advises calling a technician. Add an injector check to the yearly jobs on your maintenance schedule.
Common questions
How can you tell whether the injector or the brine valve is at fault?
Run the brine-draw test. If the brine line has strong suction during brine draw but the tank still overfills, look at the brine valve and float. If there is no suction, the injector, its screen or the drain line flow control is the more likely cause.
Can low water pressure stop the injector working?
Yes. The Fleck 5600SXT manual lists line pressure that is too low as a reason a softener fails to draw brine and says to raise it to 20 psi. Check the pressure before taking the valve apart.
Can vinegar go into the brine tank instead of taking the injector apart?
No. Quality Water Treatment says not to put vinegar in the brine tank and allows diluted vinegar only for parts removed from the valve. Take the injector out, clean it, and replace it if it will not come clean.
Does the valve need reprogramming after the injector is cleaned?
Usually you only need to set the time of day after plugging back in. If the display or settings look wrong, check them against the settings guide.
If brine still won't draw
More help: see our water softener guides.