DishwasherNot Draining?
You open the dishwasher and there’s an inch of dirty water in the bottom. Annoying — but the diagnosis is usually one of four or five things, and one of them is a fix you can probably do yourself in five minutes. Here’s the honest breakdown.
What's probably wrong
Standing water in a dishwasher almost always points to one of five things: a clogged drain filter, a knockout plug nobody removed when the garbage disposal was installed, a kinked or clogged drain hose, an air-gap blockage (if you have one), or a failed drain pump.
The first one — clogged filter — is the most common, and it’s the only one a homeowner can reliably fix without tools or a tech. The other four need eyes on the install. Here’s how to tell which is which before deciding to call.
The most common causes
Ranked by how often we see each one. The diagnostic that actually matters isn’t a guess from a list — it’s a tech listening to your machine, looking at the install, and checking the right things in the right order. But it’s useful to know what’s on the menu.
Clogged Drain Filter
Bottom of the tub has a small cylindrical filter that catches food debris. Over time it packs solid with rice, coffee grounds, and food fragments. Once it’s full, water can’t reach the drain. Pulling and rinsing it is a real DIY fix — instructions are in your owner’s manual, takes about five minutes. If that solves it, you’re done.
Garbage Disposal Knockout Plug
When a new garbage disposal is installed, the installer is supposed to remove a plastic knockout plug in the disposal’s dishwasher port. If they don’t, the dishwasher drain hose has nowhere to send water. We see this in new homes and recently-renovated kitchens. Look up inside the disposal where the dishwasher hose connects — if there’s a black plastic disc, tap it out and the problem disappears.
Drain Hose Kinked or Clogged
The drain hose runs from the back of the dishwasher up under the sink. Over time it can get pinched flat against cabinet sidewalls, or grease and food debris can build up inside. Same symptom either way — water has nowhere to go. Sometimes the fix is unkinking; sometimes the hose needs replacement.
Air-Gap Blockage (if installed)
That small chrome cylinder beside your faucet (looks like a tiny chimney) is an air gap — a backflow prevention device required in some Edmonton homes. When it clogs internally, water backs up into the dishwasher. Unscrewing the top and cleaning it out is sometimes the whole fix.
Drain Pump Failure
The pump motor that pushes water out has died. Usually preceded by louder-than-normal operation in the weeks before failure. You hear a hum or nothing at all during the drain cycle. The pump needs replacement. Bosch, Whirlpool, Samsung, and KitchenAid all use different pumps with widely varying prices (here’s why parts pricing is wild).
Garbage Disposal Itself Is Backed Up
If the dishwasher drains into the disposal and the disposal is backed up, the water has nowhere to go. Try running the disposal with cold water for thirty seconds. If it grinds clear, that may be the fix. If it hums or trips, the disposal needs attention before the dishwasher will drain — that’s a plumber call, not an appliance one.
Before you call
Worth ruling out before you book — some of these take five minutes and might save you the service call entirely:
Bottom of the dishwasher, usually a twist-out cylinder. Five minutes with the tap. If the dishwasher drains after, you’re done — no call needed.
If yes, the problem is in the shared drain line, not the dishwasher itself. That’s a plumber, not an appliance tech.
Look up inside the disposal where the dishwasher hose connects. If there’s a black plastic plug, knock it out with a screwdriver. Common new-install miss.
Sometimes the disposal itself is the bottleneck. Clearing it lets the dishwasher drain.
Write it down (E15, E24, F11, LE1, etc). The code narrows the cause and lets your tech pre-source the right part before the visit.
Why a real diagnosis matters
Dishwasher drain calls have a high “should have checked first” rate. About one in three turns out to be a clogged filter or a knockout plug — five minutes of homeowner time. We’d rather you save the service-call fee than book us for something you could fix yourself. But when it’s the pump, hose, or air gap, a real diagnosis from outside the install isn’t reliable.
Before swapping anything, we check filter, hose, knockout plug, air gap. If it’s one of those, we tell you, and the visit is just the service-call fee — sometimes waived if you genuinely didn’t need us.
A failing pump often coincides with a partially clogged drain line. We check both before quoting parts.
If your kitchen sink also backs up, the dishwasher isn’t the problem — and we don’t pretend it is. We point you to a plumber.
Bosch and Whirlpool pumps look similar and aren’t interchangeable. The model number lets us bring the right part on the first visit.
What the repair typically costs
Kodiak quotes labour as a flat rate per repair type, after diagnosis but before any work begins. Parts are quoted separately on your invoice. Typical labour ranges:
Most dishwasher drainage fixes — filter cleaning, hose un-clog, drain pump replacement, air-gap clearing — fall in the $220–$350 range for labour. Parts (like a new pump) are quoted separately when needed, and pricing varies a lot between brands.
If the diagnosis turns out to be a clogged filter or a knockout plug you could have done yourself, we’ll tell you and you’ll only pay the service-call fee. That’s the deal.
Applied toward the repair if you proceed.
Your firm quote comes from your tech after diagnosis, before any work begins. You approve before we touch anything. Full pricing details.
Ready when you are
Kodiak Appliance Repair covers Edmonton and the Capital Region. Book a time online, or call with a question — we pick up.
More resources
Dishwasher Repair Edmonton
Main dishwasher service page — all brands, all symptoms, full pricing.
Dishwasher Drain Clog DIY Fix
The step-by-step for the filter fix.
Why Less Detergent Cleans Better
How over-detergent contributes to drain issues.
Why Parts Pricing Is Wild
Why your specific dishwasher pump costs what it costs.
Honest, flat-rate appliance repair in Edmonton and the Capital Region. Run by a working tech who wants to do it right.