13 replies to this topic

[hotlicks]

Ok, I have tried everything. What am I missing. We have just the top drawer installed, no bottom. Replaced a cracked drain hose a year ago. 6 months ago the dishwasher would leave a cup to a cup and a half of water in the bottom. After a couple weeks it starts nasty black mold to growing everywhere. I blew out the drain hose, replaced the rotor, and replaced the flap valve in the drain hose. The dishwasher still leaves a cup and a half of water in the bottom. What is interesting is that I can manually activate the drain function P2 in diagnostic mode and drain 90% of the leftover water out. There is still a small puddle in the food debris area, but only about 2-4 tablespoons. Is there supposed to be any water whatsoever left in the food trap area? Any help is greatly appreciated.

[Comstock_Services]

does your dishwasher drain into an airgap? or straight to the disposal?

Yes there should be a small ammount of water in the sump area all the time, to prevent the seals from drying out.

[hotlicks]

It goes through a high drain loop and then to the disposal.

[Comstock_Services]

I would first check for a restriction, in the drain hose, and make sure to check the check valve. Does the water run from the top drawer to the bottom drawer, or you notice it in a single drawer only?

[hotlicks]

I only have a top drawer, no bottom drawer. Are you calling the check valve the little flapper that goes at the end of the drain hose that connects to the drawer? If so, I just replaced it with a brand new one and made sure it was clear. I will check the hose and make sure it is clear and let you know what I find. Thanks for the replies and help.

[hotlicks]

ok, I have now removed the drain hose and blown it out and washed it out. I checked my high loop drain hanger and I am still getting the same cup and a half of water left over after every run . I can manually drain the excess water after each run, but I can't figure out what is causing this. Anyone have any new ideas?

[DADoESTX]

My DD603 has this much water left in the filter sump as matter of normal course ... just enough water to fill the sump area, not up into the tub-proper. The spoon is for visual reference, dunno if it helps much. I'd estimate about 8 oz / 1 cup. If that's what you have, then there's no problem. A brief drain is always run at the start of a cycle. My unit is 8+ years old, haven't yet had any trouble or repairs on it.

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[hotlicks]

Thanks for the input. The problem that is occurring is that black mold and sludge begins growing after about 2 weeks. We use the dishwasher every 2-3 days. I am assuming that the mold is a direct result of water being left in the bottom. Here is a picture of the water left over. I added a drop of food coloring to the water so you could see it better. The black arrows top left and right are how high the water is staying. I cleaned the dishwasher 2 weeks ago and you can see already the beginning of the mold/slime in all the crevasses . If I do not clean all this every couple of weeks then everything below the silverware basket becomes covered in black mold and sludge. I just can't figure out why.

[DADoESTX]

Any residual water is of course thoroughly flushed out / changed / refreshed on the next cycle ... it's not two-week old water staying there. I checked my lower drawer now (the upper has a load waiting to run, didn't want to pull it all out), removed the screen, it does have the same amount of water pooling up the channel. I've never had mold, even if a drawer is left unused long enough that the residual water (perhaps with some bits of food debris) completely dries away. You may have some contributing factor involved ... usage habits maybe? What cycle do you use most often? What detergent and at what dosage?

[Samurai Appliance Repair Man]

Also, using too much detergent with the wash will leave some residual amount behind in the standing water. Detergent residue is NOT anti-bacterial and is an excellent source of carbon and nitrogen to support bacterial growth. Warm, dark, wet place + food source = mold. Common problem in washing machines, too, from using either too much or the wrong type of detergent. Fun fact to know and tell.

[hotlicks]

we are using cascade complete powder and we always run the normal cycle ( 69 minutes ) Any thoughts on this? Something has to be causing this because this drawer is 5 years old and just started doing this 6-12 months ago.

[DADoESTX]

I'm not directly familiar with cycle times on 602 but 69 mins seems too short for the Normal cycle, either Eco or non-Eco. My DD603 is 115 mins for Normal, 88 for Normal Eco. F&P did/does occasionally change the cycle profiles, so maybe yours is correct for that model.

Also curious how you have a 602 that's five years old when my DD603 is 8+ years.

Maybe try running the Heavy (non-Eco) cycle for a while to get the highest target temps, see if that has any effect on the moldy-ness.

Try a different detergent. There's institutional bleach-formula Cascade available (but may have to buy it in a large quantity) that still also has phosphates.

Rinse aid? Reduce the dosage?

[hotlicks]

You are correct. It is older than 5 years. We have only been at the house for 5 years, but it was installed before we moved in. The institutional bleach-formula Cascade you mentioned with phosphates. Are the phosphates good or bad, desired or not in a detergent? What are the pros/cons?

[Samurai Appliance Repair Man]

Phosphates were used in detergents because they would "run interference" on the hardness minerals in the water by binding them up and preventing them from screwing with the surfactants in the detergent-- the REAL part of the detergent that breaks down the surface tension of water and makes water "wetter" so it can remove soils. The problem with phosphates was that they tended to make it all the way through to the outfall of the sewage treatment plant and into the environment where they acted like a superfood for water plants and algae, making them grow unnaturally fast and thus sucking up all the oxygen in the water and killing fish.

The detergent manufacturers voluntarily removed phosphates in July of 2010 and since then we professional appliantologists have been inundated with washability complaints in dishwashers (mostly) and washing machines, too. ==> Coping with Phosphate-free Dishwashing Detergents

Some work-around methods are explained here ==> Dishwashers and hard water: getting the best possible results