Do-It-Yourself Story

It finally gave E15 code, then after drying out the E15 code came back within 5 minutes of running. I dried out the base then I ran the dishwasher and observed water coming down the overflow chute after running only 5 minutes.There is a water inlet (clear water chamber on the side of the machine). It had some gunk inside that was stopping a black float shut-off from moving. I replaced the water inlet chamber. I also suspected the non return valve (also called a check valve). From the parts diagram I could see the valve is inside the hose connection inside the sump. This is criminal because previous Bosch models and most other brands have the non return valve accessible after removing the filter. There is usually a cover that allows you to remove and replace the rubber diaphragm from inside the tub. I almost think this is planned obsolescence!! They know this is a service part at least once in the life of a machine. Anyway, this Bosch model requires you to remove the whole bottom of the machine because the hose is captured by a "U" shaped protrusion that is part of the base. There is a ridge in the hose and then the hose sits down in the "U" so the hose doesn't slide out. Instead of removing the machine base, I cut off the left side of the "U" at about the 9:30 position and wiggled the hose out easily. The check valve is clicked inside the sump by a slight ride inside the sump outlet. They make it very difficult to remove without damaging the inside of the outlet. The check valve needs to be spun counterclockwise about 1/4 turn releasing it from the ridges. This will be a bit of a fight with tools you may have on hand, Be careful not to scratch the inside of the sump outlet since the O ring on the hose needs to seal to this surface. After removing the non return valve I drilled a 1/4" hole in the U shaped protrusion in the 4:30 position (relative to the hose), to allow a zip tie to pass through. The new nonreturn valve has a straight rib on the inside of the valve. This rib will point down to the 6:00 position when the valve is installed correctly.Be sure to install the new valve with the rubber flap toward the sump. I installed the valve so the rib was pointed down to the 6:00 position. I then used a small flat screw driver on the edge of the valve to pop the valve past the ridges inside the sump outlet. The ridges are really small. If you see one ride peeking out past the valve you have pushed it in far enough. I installed a new hose using silicone grease inside the sump outlet. You can get silicone grease at a scuba supply store or on Amazon. Use the grease on all hose connections that have an O ring connection. Since replacing the water inlet chamber and the check valve the machine has worked fine. I noticed the rubber diagram-flap on the old non return valve was bent inwards so I suspect at times it was not closing.