What to Do When Your Dishwasher Has Dirty Standing Water

Dishwashers are notoriously prone to clogging and not draining properly due to the kinds of materials it consistently cleans from your dishes. Food particles, broken plastic utensils even stickers you forgot to remove from cups and plates. If your dishwasher is having a problem where its standing water is dirty, this could be the result of a clog, but also of a malfunctioning part. The good news is that by looking at the water stuck in your dishwasher, you have already narrowed down the problem.

Clogs in Your Plumbing

Because a dishwasher is so complex, there are a number of places where clogs could be causing water to back up or prevent it from draining properly. The easiest place to start is the drain hose under your sink that connects to your washer. Sometimes these pipes are clear and you can see whether there is blockage or water inside, but if not, disconnecting it only requires a wrench and a bucket to catch excess water. Make sure you turn off your house water before doing any plumbing work.

If the drain hose is clear, there's a good chance that some part of the actual drain mechanism is clogged. You'll have to take apart your dishwasher to take a look, but most washers function the same way, and it's easy to figure out.

  1. Take out all of the drawers
  2. Unscrew the main rotating arm, which is usually on the bottom covering the drain
  3. Remove the filter, then remove the cover below to expose the blade and honeycomb grid

The main places you will find clogs are on the underside of the top filter, along the honeycomb grid and on the blade assembly. While you may find a clear reason for the blockage in one area, you should take the time to clean everything while you have it all apart.

While you're at it, test the blade by gently spinning it with your finger. There should be a small amount of resistance, but it should spin easily and smoothly. If there is too much resistance or it feels like it might break it you apply too much pressure, you may need to have the blade examined or replaced by a professional.

Malfunctioning Check Valve

The check valve is what lets dirty water drain from the bottom of your washer while also keeping dirty water from flowing back in. This can sometimes malfunction in a few different ways, but if you're seeing a problem with dirty water, it's likely that the problem is that it is not closing properly after the water drains. In turn, dirty water that should be draining is flowing back into your dishwasher and sitting there.

If this is the case, there's nothing wrong with your drain; the check valve just needs to be fixed. If the check valve is simply stuck, you can attempt to clean it out yourself. Look for a rubber flapper on the outlet area of the drain hose. If this doesn't work, you may need to hire someone to try to repair it (such as A-1 Appliance Service).