Dishwasher not cleaning properly
Poor wash results have more everyday causes than mechanical ones.
Not urgent Poor cleaning is an inconvenience rather than a hazard, though it is worth sorting out before a wash pump or heater problem gets worse.
What this symptom usually means
Poor wash results have more everyday causes than mechanical ones. A filter that has not been cleaned in months recirculates dirty water. A spray arm blocked by a tall pot, or with its holes plugged by seeds and glass, cannot reach the far corners. Water that arrives cold means detergent never activates; GE's guidance is that the supply should reach about 49 °C (120 °F) at the sink. Detergent that has gone lumpy in a humid cupboard, hard water with no rinse aid, and a quick cycle on a heavy load all show up as film, grit or dried-on food.
If the basics are right and results are still poor, the dishwasher may not be filling enough (a partly blocked inlet valve or low household pressure), the wash pump may be weak or its impeller worn, the heater may not be raising the water temperature, or the detergent door may not be opening on time. A gritty residue on glasses often points to a filter or sump problem; a white film points to water hardness or rinse aid.
Checks you can do yourself
- Clean the filter and sumpTwist out the filter under the lower rack, clean it under the tap with a brush, and wipe out the sump area. Do this monthly.
- Free the spray armsSpin each arm by hand; it should turn freely and not hit anything in the rack. Remove the arms if the manual allows and rinse them, clearing blocked holes with a toothpick.
- LoadingFace dirty surfaces toward the centre, do not nest bowls, and keep tall items from blocking the upper arm or the detergent door. Scrape but do not pre-rinse; modern detergents need a little soil to work.
- Water temperatureRun the kitchen tap hot before starting the dishwasher. Avoid running it while a shower or the washer is using hot water. If the tap never gets hot, that is a water-heater issue.
- Detergent and rinse aidUse fresh automatic dishwasher detergent in the amount the manual gives for your water hardness. Fill the rinse aid dispenser; on the Ottawa and Gatineau municipal supply many households still find rinse aid makes a visible difference.
- Cycle choiceUse a heavier cycle or a heat/sanitise option for pots and baked-on food. Quick cycles are for lightly soiled loads.
- Run a cleanerRun an empty cycle with a dishwasher cleaner or a cup of white vinegar in the top rack to clear grease and mineral film.
Nothing above involves gas, wiring, refrigerant or removing panels.
What our technician checks
These need panels off, live electrical tests or a licensed trade, so they are left to the technician:
- Removing the pump or heater from beneath the tub
- Testing the inlet valve or heater electrically
- Work on the household hot-water supply
Gas appliances, commercial equipment, and Thermador, Miele, Viking, Wolf and Fisher & Paykel appliances: $129 + tax.
Waived when you proceed with the repair. You get the cause, the price and our repair-or-replace verdict in writing before any work.
Repairs a technician may recommend
After inspection, not from the symptom alone.
Wash pump or motor replacement
When water pressure at the spray arms is weak with a clean filter and full fill; the technician checks the impeller first.
Water inlet valve replacement
When the tub fills below the level the manual specifies, often because the valve screen is silted.
Heating element or thermostat replacement
When water in the tub stays cool through the wash and dishes come out greasy and wet.
Spray arm replacement
When an arm is cracked or its bearing is worn so it no longer spins.
Detergent dispenser replacement
When the door does not open or opens before the wash starts and the tablet is found intact or stuck.
Control board or sensor replacement
When cycles run short or skip the main wash on models with soil sensors.
Brands we see with this problem
Codes, parts and access differ by brand; the brand pages cover where the model label is and what to expect.
Cost, and whether to fix it
What the repair costs depends on the part, the labour and whether a second visit is needed for an ordered part; the written finding gives the total before any work. Our guides on what drives repair costs, dishwasher repair costs and repair versus replacement explain how to weigh it.
Who to call
RepairWell diagnoses and repairs this in homes and businesses across Ottawa and Gatineau; the diagnostic ($89 + tax at home, $129 + tax for a business) is waived when you proceed with the repair. If the dishwasher is still under the manufacturer's warranty, contact the manufacturer first: warranty repairs usually have to go through their authorized network.
When to book
Book when a clean filter, free spray arms, hot water at the tap and fresh detergent have not fixed it, or when you notice the tub is filling less than it used to, the water inside stays cold, or the detergent tablet is still in the dispenser at the end. Tell us what you see on the dishes (grit, white film, greasy, food left on the top rack only); each points somewhere different. The diagnostic visit is $89 + tax, waived when you proceed with the repair. Dishwasher repair has the full scope.
We handle this across Ottawa and Gatineau
Related problems
Dishwasher not cleaning properly: questions
Should I rinse dishes before loading?
Scrape, don't rinse. Manufacturers say detergent enzymes need some soil to act on, and pre-rinsed loads can fool soil sensors into running a lighter wash.
Glasses come out cloudy. Is the dishwasher broken?
Cloudiness is usually hard-water film (wipes off with vinegar) or etching (permanent, from soft water and too much detergent). Neither is a mechanical fault. Adjust detergent and rinse aid first.
Only the top rack comes out dirty. Why?
The upper spray arm may be blocked by a tall item, its supply tube may be clogged, or the arm may have come loose from its mount. Check the arm turns freely; if it does and results are still poor, book.
Does the dishwasher need hot water from the tap?
It helps. Most dishwashers heat water, but they start from what arrives. Running the tap hot first shortens the cycle and improves the wash on most models.
Sources
Sources checked 2026-09-24.
From the repair blog
Repair stories and guides, with real photos from our work.
Book the diagnostic
Tell us this symptom and your postal code; it helps us bring the right parts.
Pick a preferred day and arrival window online; we confirm by email once a technician is assigned.
- $89 + tax diagnostic$129 + tax for gas or commercial appliances and for Thermador, Miele, Viking, Wolf or Fisher & Paykel; waived when you proceed with the repair
- Written finding on every visitCause, price and our repair-or-replace verdict
- 90-day warrantyOn parts replaced; labour depends on the work done