Skip to content 
You open the dishwasher expecting clean dishes and instead find a pool of dirty water sitting in the bottom. It’s one of the most common dishwasher problems there is — and while it looks alarming, the cause is usually something specific and identifiable. In a lot of cases, you can resolve it yourself in under half an hour.
We repair dishwashers across Winnipeg, and standing water is one of the calls we get most often. Here’s a clear, step-by-step look at what causes a dishwasher not to drain — starting with the simplest fixes and working toward the ones that need a technician.
Quick answer: why won’t my dishwasher drain?
A dishwasher that won’t drain is most commonly caused by a clogged filter, a blocked or kinked drain hose, a clogged garbage disposal or air gap, or a failed drain pump. Food debris and grease buildup are behind the majority of these blockages. The standing water itself is almost always a sign that something is physically obstructing the path water takes to leave the machine.
Before you start, a safety note: always turn the dishwasher off at the breaker before reaching into it or working on any components. And have towels and a shallow container ready — you’ll need to scoop out the standing water first.
Start here: remove the standing water
Before diagnosing anything, scoop out as much of the standing water as you can with a cup or small container, then soak up the rest with towels. You can’t properly inspect the filter or drain area with water sitting on top of it, and you’ll make less of a mess working on the machine afterward. This step alone tells you nothing about the cause — but everything that follows is easier with the tub empty.
The most common causes — from simplest to most complex
1. Clogged filter
This is the number one cause of a dishwasher that won’t drain, and the easiest to fix. The filter sits at the bottom of the tub and catches food particles so they don’t recirculate. When it becomes saturated with debris, water can’t pass through to the drain.
Most modern dishwashers have a cylindrical filter that twists out from the floor of the tub. Remove it, rinse it under warm running water, and use a soft brush to clear any trapped food, grease, or buildup. While the filter is out, check the area underneath it for larger debris — broken glass, labels from jars, seeds, and bones are common culprits. Cleaning the filter regularly prevents this problem from recurring.
2. Blocked or kinked drain hose
The drain hose carries water from the dishwasher to your home’s drain system. If it’s kinked, crushed, or clogged with debris, water can’t get through. The hose runs from the back of the dishwasher to either the garbage disposal, the sink drain, or an air gap on the counter.
Check the visible portion of the hose behind or under the machine for sharp bends or crushing — this sometimes happens if the dishwasher was pushed back too far against the wall. A clog inside the hose is harder to spot and may require disconnecting the hose to clear, which is a job some homeowners are comfortable with and others prefer to leave to a technician.
3. Clogged garbage disposal (if connected)
If your dishwasher drains into a garbage disposal — common in many Winnipeg kitchens — a clog in the disposal will stop the dishwasher from draining. Run the disposal to clear any food waste sitting in it and try the dishwasher again.
There’s also a specific issue worth knowing about: if a garbage disposal was recently installed, the knockout plug — a small plastic cap covering the dishwasher drain connection — may not have been removed during installation. If your dishwasher has never drained properly since a new disposal went in, this is very likely the cause and needs to be cleared.
4. Blocked air gap
Many kitchens have an air gap — a small cylindrical fitting mounted on the counter next to the faucet that prevents dirty water from siphoning back into the dishwasher. Over time it can become clogged with debris, which blocks drainage. If you have an air gap and water bubbles up from it during a cycle, that’s a sign it’s blocked. Remove the cap and clear any buildup inside.
5. Failed drain pump
The drain pump is what actively pushes water out of the dishwasher at the end of the cycle. If the filter, hose, disposal, and air gap are all clear and the dishwasher still won’t drain, the pump itself may have failed — either the motor has burned out or something is jamming the impeller.
You may hear a humming sound without water actually draining, which suggests the pump is getting power but can’t move water. A failed drain pump needs to be tested and replaced by a technician, as it involves accessing components beneath the machine and confirming the electrical supply.
6. Faulty drain solenoid or control issue
Some dishwashers use a solenoid to open the drain valve at the right point in the cycle. If it fails, the valve doesn’t open and water stays in the tub. Less commonly, a fault in the control board can prevent the drain cycle from triggering at all. Both require diagnosis by a technician with the right tools.
A quick test to narrow it down
Once you’ve cleaned the filter, run a short rinse cycle and listen. If you hear the pump engage and water drains, the filter was the issue. If you hear the pump humming but no water moves, the problem is likely a blocked hose, disposal, or a failing pump. If you hear nothing at all when the drain cycle should start, the issue may be electrical — a failed pump motor, solenoid, or control board. This simple listening test helps a technician zero in on the cause faster, too.
When to call a technician
The filter, drain hose, garbage disposal, and air gap are all things most homeowners can check and clear without special tools. If you’ve worked through all of those and the dishwasher still holds water, the issue is mechanical or electrical — a failed drain pump, solenoid, or control board — and that’s where a technician comes in.
It’s also worth calling sooner rather than later if water is leaking onto the floor, if there’s a burning smell, or if the machine is making unusual noises during the drain cycle. Continuing to run a dishwasher with a failing pump can damage other components and turn a single-part repair into a larger one.
We diagnose and repair dishwashers across Winnipeg and surrounding areas — same-day or next-day service in most cases. If your dishwasher won’t drain and the simple fixes haven’t worked, we can find the cause and sort it out properly.
Learn more about our dishwasher repair service →
Frequently asked questions
Why is there standing water in the bottom of my dishwasher?
Standing water means something is blocking the drainage path. The most common causes, in order of likelihood, are a clogged filter, a blocked or kinked drain hose, a clogged garbage disposal, a blocked air gap, or a failed drain pump. Start by cleaning the filter — it resolves the issue more often than any other single fix.
Can I fix a dishwasher that won’t drain myself?
Often, yes. Cleaning the filter, checking the drain hose for kinks, clearing the garbage disposal, and cleaning the air gap are all tasks most homeowners can do without special tools. If those don’t resolve it, the cause is likely a failed drain pump or an electrical fault, which requires a technician.
Is a little water in the bottom of the dishwasher normal?
A small amount of clean water in the filter area at the bottom is normal in many models — it keeps the seals from drying out. What’s not normal is a noticeable pool of dirty water sitting in the tub after a complete cycle. That indicates a drainage problem that needs to be addressed.
Why does my dishwasher hum but not drain?
A humming sound without water draining usually means the drain pump is receiving power but can’t move water — either because something is jamming the impeller or because the pump motor is failing. Turn off the machine and check for debris around the pump area if accessible. If nothing is visibly blocking it, the pump likely needs to be replaced by a technician.
How often should I clean my dishwasher filter to prevent drainage problems?
Every four to six weeks for most households, and more often if you run the dishwasher daily or frequently wash heavily soiled dishes without rinsing first. A clean filter is the single most effective way to prevent drainage problems and keep the dishwasher cleaning well.
How quickly can Fix Up Pro come out for a dishwasher repair in Winnipeg?
In most cases we can schedule a same-day or next-day visit across Winnipeg and surrounding areas. You can book online or call us directly — whichever is easier for you.