--- title: "Kenmore 350 Water Softener Troubleshooting" canonical: "https://gadgetguides.org/kenmore-350-water-softener-troubleshooting/" author: "Arian" published: "2026-09-12T22:52:39+00:00" modified: "2026-09-12T22:52:39+00:00" language: "en-US" site: "Gadget Guides" description: "Your Kenmore 350 is supposed to make your water feel silky, keep your pipes scalefree, and save you from scrubbing soap scum off every shower door. But…" categories: "Help Guide" attribution: "Gadget Guides (https://gadgetguides.org/)" --- # Kenmore 350 Water Softener Troubleshooting Your Kenmore 350 is supposed to make your water feel silky, keep your pipes scale-free, and save you from scrubbing soap scum off every shower door. But when it stops working right, you're stuck with hard water and a machine that just sits there taking up space. That's exactly where Kenmore 350 Water Softener Troubleshooting comes in. This guide walks you through the most common failure points step by step, starting with the simplest fix and moving to the deeper stuff only if you need it. Per manufacturer specifications, most Kenmore 350 problems come down to just three things: salt issues, a clogged venturi, or a bypass valve left in service mode by accident. As of 2026, replacement parts for this model are still widely available, and the average DIY repair runs about 45 minutes and under $50 in parts. Let's run the diagnostic sequence so you can get your soft water back without guessing. ## Quick Answer Start with the bypass valve. If it's in bypass mode, your water bypasses the softener entirely. Check the salt level and break any salt bridge. Inspect the venturi for clogs. Manually advance the timer to force a regeneration. If none of those work, test the drive motor. Most fixes take under an hour. ## Why Your Kenmore 350 Isn't Working (And How to Think Like a Repair Tech) A water softener is a simple machine when you strip away the tank and the timer. It pushes hard water through a bed of resin beads. Those beads trap the calcium and magnesium. Eventually the beads get full and need a salt brine rinse to recharge. That rinse is called regeneration. When something in that cycle breaks, you get hard water, salt tank problems, or a unit that won't run at all. The Kenmore 350 is a metered model. It tracks how much water you use and regenerates only when needed. That's efficient, but it also means the electronics, drive motor, and piston assembly have to work reliably every time. When one piece fails, the whole system stops. Here's what's inside your Kenmore 350 that matters for troubleshooting: - **Control valve assembly:** The brain and the muscle. Contains the timer or circuit board, drive motor, and piston that directs water flow. - **Venturi / injector:** A small plastic assembly that creates suction to pull brine from the salt tank into the resin tank during regeneration. - **Brine tank:** The white or black tank where you pour salt. Holds the salt and water mixture that makes brine. - **Resin tank:** The tall green or blue tank filled with resin beads. This is where the actual softening happens. - **Bypass valve:** A plastic valve with a handle that lets you isolate the softener for service without shutting off water to the whole house. Most of the time, the problem isn't the resin or the tank. It's the venturi getting clogged with salt grit, the bypass valve being in the wrong position, or a salt bridge forming in the brine tank. All of those are easy fixes you can do in a few minutes with no tools. ![Kenmore 350 Water Softener Troubleshooting](https://gadgetguides.org/wp-content/uploads/2026/09/kenmore-350-water-softener-troubleshooting-mtyzdal0.webp) Image source: Bing (Web (fair-use with source credit)) ## Decision Tree #1: Water Is Still Hard This is the most common complaint. Your water feels hard again. Soap doesn't lather well. You're seeing spots on dishes. The unit seems to be running, but the water coming out is no better than before. Here's how to trace the problem. ### Check bypass valve position Start here every time. The bypass valve on the Kenmore 350 has two positions: service and bypass. In service mode, water flows through the softener. In bypass mode, water goes straight to your pipes untreated. Someone might have bumped the handle during cleaning or maintenance. If the handle is parallel to the pipes, you're in service mode. That's correct. If it's perpendicular or rotated 90 degrees, you're in bypass. Rotate it back to service position and wait about 10 minutes. Run a faucet and see if the water feels softer. ![Kenmore 350 bypass valve](https://gadgetguides.org/wp-content/uploads/2026/09/kenmore-350-bypass-valve-mtyzdb8d.webp) Image source: Bing (Web (fair-use with source credit)) ### Verify salt level and salt bridge condition Open the brine tank lid and look inside. The salt should be at least half full. If it's low, add salt. But also look carefully at the surface. If you see a hard crust on top with a gap underneath, you have a salt bridge. That crust prevents the salt from touching the water, so no brine gets made. To check for a salt bridge, gently tap the side of the tank near the top. If the surface moves or wobbles independently of the water underneath, you've got a bridge. Use a broom handle to carefully poke through the crust and break it up. Push the pieces down into the water below. Don't use metal tools. You could puncture the tank. ### Inspect venturi / injector for clogs If the bypass is correct and the salt is fine, the next stop is the venturi. This small plastic assembly sits on top of the control valve. It has a screen and a small nozzle that can get clogged with salt grit or sediment. Remove the venturi cover. It usually snaps off or unscrews. Pull out the screen and the nozzle. Rinse them under running water. Use a toothpick or a small brush to clear the tiny hole in the nozzle. Reassemble and run a manual regeneration. If the venturi was clogged, you'll hear the water start flowing into the brine tank again. Manufacturer specifications indicate the venturi should draw brine at a rate of about 0.5 to 1 gallon per minute during the brine draw cycle. If you see no suction or very slow flow, the venturi is almost certainly the culprit. ### Evaluate resin bed age and fouling If none of the above works, the problem might be the resin itself. Resin beads last about 10 to 15 years under normal conditions. If your Kenmore 350 is older than that, the beads may be worn out or fouled with iron or manganese. Aggregate user reviews report that a resin bed replacement costs about $100 to $150 in parts and takes about two hours. You can buy replacement resin from most hardware stores or online. Follow the manufacturer's instructions for draining the old resin and pouring in the new. Before replacing the resin, try a resin cleaner treatment. Products like Iron Out or a generic resin cleaner can remove iron buildup that is coating the beads. Pour the cleaner into the brine well and run a manual regeneration. If the water improves, you saved yourself a full resin replacement. ## Decision Tree #2: Salt Tank Overflowing or Not Using Salt This pair of symptoms sounds opposite, but they often share the same root cause. If your brine tank is overflowing with water, something is keeping the system from drawing that brine into the resin tank during regeneration. If the salt level never drops, the venturi or the drain line is the problem. ### Diagnosing a salt bridge (and how to break it) A salt bridge is a hard crust that forms above the water line in the brine tank. It happens when salt dissolves and then recrystallizes into a solid layer. The water sits below the bridge, but fresh salt above it never makes contact. Break the bridge with a broom handle. Push straight down in several spots around the tank. You'll feel the crust crack. Push the pieces below the water line. After breaking the bridge, the salt will dissolve properly, and the softener should start using salt again. To prevent future bridges, keep the salt level below the top of the brine tank's inner well. Also, use high-purity salt pellets with less insoluble material. Some users report that salt crystals are less prone to bridging than pellets, but either works if you keep the tank from getting too full. ### Mushy salt sludge: causes and cleanup Over time, salt impurities and dirt accumulate at the bottom of the brine tank. This forms a thick, mushy sludge that prevents the salt from dissolving efficiently. If you push a broom handle down and feel soft mush instead of solid salt, you need to clean the tank. Drain the brine tank by siphoning the water out or using a wet-dry vacuum. Remove all the salt and sludge. Scrub the inside of the tank with a mild bleach solution, one cup of bleach per gallon of water, to kill any bacteria or algae. Rinse thoroughly. Refill with fresh salt. Plan to do this deep clean once a year. It takes about an hour and keeps the tank free of sludge buildup that can cause all kinds of problems. ![salt bridge water softener](https://gadgetguides.org/wp-content/uploads/2026/09/salt-bridge-water-softener-mtyzdcn9.webp) Image source: Bing (Web (fair-use with source credit)) ### Float assembly failure and water level in brine tank The Kenmore 350 has a float assembly inside the brine tank that controls how much water is added during the brine fill cycle. If the float sticks or the mechanism breaks, the tank can overfill. Check the float by lifting it gently. It should move freely up and down. If it's stuck, clean the float stem and the guide. If the float is cracked or damaged, replace the entire assembly. Part numbers are available from Sears Parts Direct for about $20. Normal water level in the brine tank after regeneration should be about 6 to 8 inches deep. If it's significantly higher, the float isn't working, or the brine fill cycle is too long. On older models you can adjust the timer settings to shorten the fill time. On newer models the programming is fixed. ## Decision Tree #3: Unit Won't Regenerate or Runs Continuously A softener that never regenerates lets hard water through eventually. One that runs constantly wastes salt and water. Both are annoying, but both are fixable. ### Timer or circuit board issues On the Kenmore 350, the timer or circuit board tells the drive motor when to start and stop regeneration. If the board fails, the unit might not regenerate at all, or it might get stuck in one cycle. First, check if the unit has power. Verify that the transformer is plugged in and the outlet works. If the display is blank or the timer isn't advancing, the transformer or circuit board might be dead. Replacement boards cost about $50 to $80 and are straightforward to swap out. If the timer is mechanical, which is the case on older models, listen for the motor running. If you hear nothing, the motor might be bad, or the timer gears could be stripped. Open the timer cover and inspect the gears. Replace the entire timer assembly if you see cracked or missing teeth. ### Drive motor problems (humming vs. silent failure) The drive motor turns the piston that routes water through the different regeneration stages. If the motor hums but the piston doesn't move, the gears are likely stripped. If there's no sound at all, the motor might be dead or not getting power. You can test the motor with a multimeter. Check for voltage at the motor terminals during the regeneration cycle. If you have voltage and the motor doesn't spin, replace the motor. Motors for the Kenmore 350 cost about $40 to $70 and come with the gear assembly attached. ### Stuck piston or broken gear train Even if the motor works, the piston inside the valve can stick due to hard water mineral deposits or debris. If the motor is running but nothing is happening, remove the piston and inspect it. Clean it with a mild acid like vinegar or a commercial descaler. Lubricate the seals with silicone grease designed for water softener valves. If the gear train inside the motor assembly is broken, the motor will spin freely but won't move the piston. Replace the motor assembly as a unit. Trying to repair the tiny plastic gears inside is rarely successful and not worth the time. ## Step-by-Step: Cleaning the Venturi / Injector Assembly This is the single most effective maintenance task you can do on a Kenmore 350. It takes about 15 minutes and costs nothing. Here's exactly how to do it. **Step 1: Put the softener in bypass mode.** Turn the bypass handle so it's perpendicular to the pipes. This stops water flow to the softener so you can work on it safely. **Step 2: Locate the venturi assembly.** On the Kenmore 350, it's a small rectangular or round cap on top of the control valve. It usually has two or three screws holding it on, or it snaps into place. **Step 3: Remove the venturi cap.** Unscrew the screws or gently pry off the snap-on cover. You'll see a small screen and a plastic nozzle with a tiny hole in the center. **Step 4: Remove the screen and nozzle.** Lift them out. The nozzle is usually held in by friction. Gently pull it with your fingers. **Step 5: Clean the screen.** Rinse the screen under warm tap water. If it has mineral buildup, soak it in vinegar for 10 minutes and scrub with an old toothbrush. **Step 6: Clean the nozzle.** Use a toothpick, a paperclip, or a small brush to clear the tiny hole in the center of the nozzle. Don't use a drill bit or anything that could enlarge the hole. The hole size is engineered precisely. **Step 7: Reassemble.** Put the nozzle and screen back in place. Reattach the venturi cap and tighten the screws. Rotate the bypass handle back to service position. **Step 8: Run a manual regeneration.** Press the regeneration button on the control panel. Listen for the water flowing and the brine being drawn. Within a few minutes, you should hear the water level in the brine tank dropping as brine is pulled into the resin tank. ## Frequently Asked Questions ### How do I reset my Kenmore 350 water softener? Press and hold the regeneration button for 5 seconds. This forces a manual regeneration. The unit will cycle through all stages and return to service. If the display is frozen, unplug the unit for 30 seconds and plug it back in. ### Why is my Kenmore 350 not using salt? A salt bridge is the most common cause. Check for a hard crust above the water line and break it with a broom handle. Also check for a clogged venturi that prevents brine from being drawn out of the tank. ### What does the flashing display mean on my Kenmore 350? A flashing display usually indicates an error code. Count the number of flashes and consult your manual. Common codes include motor failure, sensor issues, or a stuck piston. A single steady flash often means the unit is in regeneration. ### How often should I clean the venturi on my Kenmore 350? Clean the venturi every six months or whenever you notice a drop in water pressure or hard water returning. If you have well water with high sediment, clean it every three months. ### Can I use potassium chloride instead of salt in my Kenmore 350? Yes. Potassium chloride works the same way as salt for softening. It's better for people on low-sodium diets. The tradeoff is that it costs about three times more and can be harder to find in stores.