We have tried Affresh several times and it does not change anything. There is no question in my mind that the problem is a water drainage issue, as there is standing water in the basin after nearly every (but not every) wash. A friend who is fairly knowledgeable about home appliances thinks that the float or float switch aren't working properly, but our manuals make no mention of either component.
If there is water left in the unit after the cycle is complete and the drain system is clear then you have an air gap issue.
What is happening is the water is being pumped out, and after the pump stops pushing the water, the remaining water in the first part of the drain hose slides back into the unit.
Installing an air gap will prevent this from happening. If an air gap is already installed you need to clean it out. Mold will plug them up (You should see what my moms looked like. YUCK!) and cause this problem.
Another thing that will help is leaving the door open a bit when the unit is not in use. The higher the moisture content inside the unit the more the mold will grow.
As for the float switch that is a possibility, but the float is not the only determining factor for stopping the pump.
I have no idea what "installing an air gap" means or how to do so, so your reply is not at all useful. Further, if a problem with the float/float switch is a possibility - which you acknowledge might be the case - guidance on how to access/clean/replace it would have been useful. I realize that $19 isn't much to pay for advice, but I was hoping to get some advice that would help me solve the problem, and so far it hasn't. I don't mean to be short, but this has frustrated us for a long time and we're tired of handwashing our dishes as we stand next to our non-working "top of the line" appliance.
You are right - I should have asked. Can I 'undo' the bad mark?
Thank you. I understand the frustration with the rating system, and again apologize for jumping the gun instead of asking for more info & clarification. I won't be able to do anything further until tomorrow, but will let you know how it goes! I assume that I will need to purchase the air gap and, if needed, the float switch from a hardware store, etc.; do you know who is most likely to carry them (i.e., Home Depot, Lowe's), or will I most likely have to buy from an on-line source? Thanks again.
Stan, the air gap is a common item available from any hardware store.
The float you will have to go to an appliance parts store to order. Bosch doesn't have any on line resources to order the part from.
Just look in your local phone book under appliance parts.
It took me a while to get back to this because none of the appliance stores in Savannah had an air gap. What I learned in the process, though, is that plumbing code here requires that the drain hose has a 'loop' in it between the appliance and the drain itself. Mine doesn't! The technician who advised me of this said that the loop functions in much the same way as the air gap, and will probably fix the problem. I'll be putting everything back together this afternoon, then will run it empty with an Affresh tablet. Fingers Crossed!
We've started using the dishwasher again, but will obviously have to give it some time to determine whether the problem returns. I now know enough to troubleshoot it again, but overall I'm just not very happy with the Bosch unit.
Thank you again for your help and follow up!