The Real Reason Your Dishwasher Isn’t Draining Properly
Few things are more frustrating than opening your dishwasher after a cycle and finding a pool of dirty water sitting at the bottom. Not only does it mean your dishes aren’t properly cleaned, but it also leaves you wondering if something’s broken. The truth is, a dishwasher that won’t drain is a common household problem – and in most cases, the cause is something simple you can fix yourself. Before you panic or call for help, it’s worth knowing the real reasons this happens and what you can do about it.
How Your Dishwasher Drains
Every dishwasher follows the same basic process: it washes, rinses, then pumps the dirty water out through a drain hose connected to your sink’s plumbing. For that to happen smoothly, a few key parts need to do their job:
- Filter – catches food scraps before they clog the pipes.
- Drain pump – pushes water out at the end of each cycle.
- Drain hose – carries the dirty water into your sink drain or garbage disposal.
- Air gap (if installed) – stops wastewater from flowing back into the dishwasher.
If any one of these parts is blocked, kinked, or faulty, water won’t drain the way it should. That’s why understanding the system matters — it helps you pinpoint whether the problem is something simple, like a clogged filter, or something that needs a plumber’s help.
The Most Common Reasons Your Dishwasher Won’t Drain
A dishwasher that won’t drain doesn’t always mean it’s on its last legs. In most cases, it’s one of these common issues:
- Clogged filter = water with nowhere to go. The filter traps food scraps, but if it’s packed with gunk, water can’t pass through. A quick clean often solves the problem.
- Blocked or kinked drain hose. If the hose is twisted, bent, or clogged with debris, water simply can’t escape. Straightening it out or clearing it can get things flowing again.
- Garbage disposal connection overlooked. If you’ve recently had a garbage disposal installed, the knockout plug may not have been removed. That small oversight will stop your dishwasher from draining.
- Air gap blocked with grease and food. Homes with an air gap can run into trouble if it’s clogged. A quick clean with a brush or a flush of hot water can usually fix it.
- Pump problems. If the pump has failed, no amount of cleaning will help. At this point, you’ll likely need a plumber or appliance technician to replace it.
DIY Fixes to Try Before Calling a Plumber
Before you reach for the phone, there are a few simple things you can try yourself. Many drainage issues come down to small blockages that are easy to clear.
- Clean the filter. Take out the dishwasher’s filter (usually at the base) and rinse it under hot running water. Use an old toothbrush to scrub away greasy residue and food particles.
- Check the drain hose. Pull the dishwasher out slightly and inspect the hose for kinks or bends. If it’s clogged, disconnect it and flush it with water or a plumbing snake to clear the blockage.
- Inspect the garbage disposal connection. If your dishwasher drains through a disposal unit, make sure the knockout plug has been removed. You can also run the disposal with water to clear any trapped food.
- Clear the air gap (if fitted). Twist off the air gap cap on your sink and check for food build-up. A quick clean with a small brush or a blast of hot water will usually do the trick.
- Reset the dishwasher. Sometimes, all it takes is turning the power off for a minute and restarting the cycle. This can reset error codes and get the drain cycle working again.
When It’s More Than a DIY Job
Most dishwasher drainage issues are simple, but sometimes the problem runs deeper. Here’s when it’s best to leave it to the experts:
- The water just won’t budge. If you’ve cleaned the filter, checked the hose, and tried a reset but the water is still sitting there, it could point to a pump or motor issue.
- Multiple drains are backing up. If water is pooling not just in your dishwasher but also in the sink or other drains, the blockage may be in your home’s plumbing system, not the appliance itself.
- Strange noises or burning smells. Grinding, humming, or any kind of burning smell during the drain cycle suggests a serious mechanical fault that needs professional repair.
- Repeated drainage problems. If the dishwasher works after a clean but the same issue keeps returning, it’s often a sign of an underlying problem that a plumber can diagnose properly.
A dishwasher that won’t drain properly is frustrating, but in most cases the fix is simple. A blocked filter, clogged hose, or a quick reset is often all it takes to get things working again. If the problem keeps returning, or if you notice water backing up in other drains, it may point to a bigger plumbing issue that needs professional help.
If you’re in Adelaide and your dishwasher still isn’t draining, call Best Plumbers Adelaide. Our team can quickly find the cause and get your kitchen back to normal.
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