Dishwasher runs but dishes come out dirty

Q: Dishwasher runs but dishes come out dirty

In Canada, when a dishwasher runs but dishes come out dirty, the most common cause to rule out is a clogged filter and grease-caked spray arms — food and grit block the jets, so cleaning the filter and clearing the spray-arm holes fixes it more often than not. Next, check how it's loaded (tall items shouldn't block the arms), that you're using fresh detergent with the rinse-aid topped up, and that the incoming water is genuinely hot. A white chalky film usually points to hard water, common across much of Canada. Persistent poor cleaning after all that can mean a worn wash pump — an appliance-tech repair. If you ever smell something burning or electrical, stop and unplug it.

Frustrating — but a dishwasher that runs yet leaves food behind is almost always a cleaning or loading fix, not a broken machine.

tuneWhat are you noticing?

Select anything that matches and the checklist below reorders to fit. Not sure? Skip it.

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Start here

In Canada, start at the bottom of the tub. Twist out the cylindrical filter and rinse it under the tap — if it's packed with food, grease, or bits of glass, that's your likely culprit. Then lift off the spray arms and hold each up to the light: blocked holes mean weak spray. Cleaning both is free and fixes this more often than anything else.

Ranked from real-world failure data. The order updates as you select what you’re noticing above.

Likely causes, in the order to check them

Showing the typical order

Beginner-friendly Doable, with care Safety-critical Call a pro

handymanHow to fix it

Twist out and rinse the filter, lift off the spray arms and clear each jet hole, wipe the filter seat, then reassemble and run a rinse. No parts needed in most cases.

Pull out the bottom rack. Twist the cylindrical filter counter-clockwise (a quarter-turn on most machines) and lift it out. Watch for sharp glass or bone fragments in the debris.
Rinse the filter under a hot tap, using a soft brush and a little dish soap to cut the grease. Don't use a wire brush — it can tear the mesh.
Unclip or unscrew the spray arms (check your manual — some lift straight off, some have a central nut). Hold each up to the light and clear every blocked hole with a toothpick or thin wire, then rinse them through.
Wipe the filter seat and tub floor, refit the spray arms so they spin freely, drop the filter back in and twist to lock. Run a short hot cycle empty to confirm strong spray.

schedule20 min savings$0–10

Dishwasher cleaner (descaler/degreaser)A Canadian-market dishwasher cleaner such as a citric-acid or descaling formula; useful for hard-water film and grease buildup

gavel Check your province first AB: homeowner may do this · BC: homeowner may do this · ON: homeowner may do this · PE: homeowner may do this · QC: homeowner may do this
Cleaning the filter and spray arms is routine homeowner maintenance in every province.

visibilityHow to check

warning Hot enough to scald, so mid-cycle water is hotter stillThe whole point of this check is that the water should be hot, and a proper wash runs hotter than tap water — hot enough to scald. Open the door only briefly, keep your face and hands clear of the rising steam, and don't reach into the tub water. If measuring water temperature or opening a running cycle makes you uneasy, an appliance technician can check the fill and heat quickly.

Run the kitchen hot tap nearest the dishwasher until it's as hot as it gets, and catch some in a cup. If a kitchen thermometer reads well under about 49 C, your hot water itself is the limit — this alone can cause poor cleaning.
Start a normal cycle right after running the hot tap so the dishwasher draws hot water from the start. Many machines don't heat much on their own, so a cold first fill matters.
A few minutes in, open the door briefly and note the water in the tub floor — a proper wash should be steaming-hot and there should be a real pool of water, not a shallow trickle. Thin fills point toward the inlet valve or a stuck float.

buildthermometer schedule15 min

verifiedWhy this one goes to a pro

Reaching the wash pump means partially dismantling the dishwasher and working around its electrical connections and water lines. On a hardwired dishwasher the electrical disconnection is licensed electrician's work in much of Canada, and a mis-seated pump seal will leak. This is a job for a licensed appliance technician (and, where hardwired, an electrician) — they can confirm and fix it quickly.

gavel Check your province first AB: homeowner may do this · BC: homeowner may do this · ON: homeowner may do this · PE: homeowner may do this · QC: licensed professionals only
Appliance pump repair itself is generally owner-permitted, but if the dishwasher is hardwired, the electrical disconnection may require a licensed electrician — confirm locally before treating as DIY.

Your notes travel with the request — what you saw, what you ruled out, when it started — so the pro arrives with a head start instead of a mystery.

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Why the list is in this order

We don’t sort by likelihood alone. We sort the way a good, honest tradesperson thinks: rule out the free, safe, common causes first. That’s why the cheap checks outrank the expensive repairs — and why anything dangerous gets a hard stop instead of a pep talk. The order exists to save you money, not to sell you anything.