Most of our service area sits on groundwater, and groundwater around here is hard — Waterloo Region and Oxford County routinely measure among the hardest municipal water in Ontario. Your kettle already knows this. Your dishwasher knows it too; it just fails more expensively.
Dissolved calcium and magnesium come out of solution exactly where a dishwasher is hottest and wettest: on the heating element, inside the spray arm jets, and on your glassware. The result is a machine that still runs perfectly on paper — fills, heats, drains — while the actual washing quietly gets worse.
First: is it film, or is it etching?
Cloudy glasses have two very different causes and only one is fixable. Soak a cloudy glass in white vinegar for five minutes. If it comes out clear, that’s mineral film — hard water residue, removable, preventable. If it’s still cloudy, the glass is etched: the surface itself has been eaten away, usually by too much detergent in soft or softened water. Film means treat the water. Etching means use less detergent. Same symptom, opposite fixes.
What scale does inside the machine
Scale on the heating element acts like a sweater — the element works harder to reach temperature, runs longer, and fails sooner. Scale in the spray arm jets narrows them until the top rack barely gets rinsed, which is why the classic complaint is “the bottom rack is fine but the glasses up top come out gritty.” And scale around the door gasket and float switch is behind a surprising number of “mystery” leaks and fill errors we see on dishwasher calls in Kitchener, London and Cambridge.
The monthly fight-back: clear the filter at the tub bottom (twist, lift, rinse — two minutes), then run the hottest cycle empty with citric acid or a descaler in the detergent cup. Keep the rinse-aid reservoir filled; in water this hard it isn’t optional, it’s the difference between spotted and clear. Unscrew the spray arms once or twice a year and poke the jets clear with a toothpick.
When it’s not the water anymore
Some symptoms only look like hard water. Dishes coming out cold and dirty points at the heater or its relay, not scale. A hum with no wash action means the circulation pump. Standing water after every cycle is the drain path. And grit that appears suddenly rather than gradually is usually a torn filter or a failed chopper letting food recirculate. Those are internal repairs — and all of them are cheaper than the machine they save.
We repair every major dishwasher brand 7 days a week at regular rates. The service call is free with a completed repair and every repair carries a 90-day warranty.
Call (519) 900-3010 or book online and we’ll call to confirm. Mention this article for $25 off your repair.
Appliance Experts is locally owned — see our dishwasher repair service, or our dedicated Bosch and KitchenAid dishwasher pages.
Frequently Asked Questions
Why are my glasses coming out of the dishwasher cloudy?
Either removable mineral film from hard water, or permanent etching from too much detergent. Soak one glass in white vinegar for five minutes: if it clears, it is film and descaling plus rinse aid will fix it; if it stays cloudy, the glass is etched and you should reduce detergent.
How do I descale a dishwasher?
Run the hottest cycle empty with citric acid or a commercial descaler in the detergent cup, once a month in hard-water areas like Waterloo Region. Clean the bottom filter first and keep the rinse-aid reservoir topped up.
Why is the top rack not getting clean?
Usually scaled or clogged spray arm jets, or a weakening circulation pump that can no longer push water to the upper arm. Clear the jets first; if the top rack is still dirty, the pump needs a technician’s diagnosis.