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The Problem
Our GE Profile (PDW8480J10) dishwasher leaves food grit of a sand-like consistency on the dishes. I've attempted various solutions to this persistent, disgusting problem, which run the gamut from the simple (different detergents) to the complex (replaced the drain pump), but to no avail. The gritty stuff continues to speckle the insides of glasses and the surface of plates. I routinely dismantle the dishwasher innards to get at and clean the sump. After a few washes, the grit is back. Grrrr...
I believe the drain pump is the most likely source of the grit in the dishwasher, and the thing that creates the grit in the first place.
How dishwashers drain waste-water
A 48" drain hose directly connects between the drain pump and the garbage disposal. The disposal outlet resides 14in higher than the drain pump, which means a significant amount of waste-water remains in the drain hose after the dishwasher has finished. (The drain pump has a rubber backflow valve to prevent waste-water backflow into the sump through the drain pump when it is not active.) The drain pump must generate sufficient pressure to raise a column of standing waste-water from the bottom of the dishwasher thru the length of the drain hose and then over a foot "uphill" to discharge into the disposal. All dishwashers pretty much work this same way.
My theory
I inspected the drain pump (WD26X10039) when I had it out. I noticed that the impeller has four flat paddles rather than curved vanes (think "turbine"). Seems to me, an impeller built with curved vanes would draw waste-water efficiently and thus propell the gunky stuff out of the dishwasher like it's supposed to. I have a theory that this specific drain pump mostly just churns the waste-water which renders food scraps into sand-like particulate, the heaviest of which never get pumped out of the machine do to the inefficient design of the pump. Indeed, the OEM replacement pump shares the same impeller design. Not surprisingly, replacing the pump did not resolve the problem.
Anyway, anyone else had similar problems with their dishwasher? If so, did you discover a permanent solution?
GE Profile (PDW8480J10) dishwasher
drain pump (WD26X10039)
Our GE Profile (PDW8480J10) dishwasher leaves food grit of a sand-like consistency on the dishes. I've attempted various solutions to this persistent, disgusting problem, which run the gamut from the simple (different detergents) to the complex (replaced the drain pump), but to no avail. The gritty stuff continues to speckle the insides of glasses and the surface of plates. I routinely dismantle the dishwasher innards to get at and clean the sump. After a few washes, the grit is back. Grrrr...
I believe the drain pump is the most likely source of the grit in the dishwasher, and the thing that creates the grit in the first place.
How dishwashers drain waste-water
A 48" drain hose directly connects between the drain pump and the garbage disposal. The disposal outlet resides 14in higher than the drain pump, which means a significant amount of waste-water remains in the drain hose after the dishwasher has finished. (The drain pump has a rubber backflow valve to prevent waste-water backflow into the sump through the drain pump when it is not active.) The drain pump must generate sufficient pressure to raise a column of standing waste-water from the bottom of the dishwasher thru the length of the drain hose and then over a foot "uphill" to discharge into the disposal. All dishwashers pretty much work this same way.
My theory
I inspected the drain pump (WD26X10039) when I had it out. I noticed that the impeller has four flat paddles rather than curved vanes (think "turbine"). Seems to me, an impeller built with curved vanes would draw waste-water efficiently and thus propell the gunky stuff out of the dishwasher like it's supposed to. I have a theory that this specific drain pump mostly just churns the waste-water which renders food scraps into sand-like particulate, the heaviest of which never get pumped out of the machine do to the inefficient design of the pump. Indeed, the OEM replacement pump shares the same impeller design. Not surprisingly, replacing the pump did not resolve the problem.
Anyway, anyone else had similar problems with their dishwasher? If so, did you discover a permanent solution?
GE Profile (PDW8480J10) dishwasher
drain pump (WD26X10039)
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