Hard Water in Mississauga: What It Does to Your Dishwasher, Washer and Fridge

Mississauga gets its tap water from Lake Ontario, treated at Peel Region’s Lorne Park and Arthur P. Kennedy plants. Peel’s 2023 South Peel Water Quality Report puts its hardness at 120 to 130 mg/L, or about 7.0 to 7.6 grains per gallon. That’s moderately hard: not extreme, but enough to leave scale inside any appliance that heats water or holds it.

Here’s what that scale does to each appliance, the signs to watch for, and the simple habits that stop it from turning into a repair. For the general picture across the GTA, see our guide to how hard water damages appliances.

What hard water actually does

Hardness is dissolved calcium and magnesium. When water is heated, or sits and evaporates, those minerals come out as limescale: the white crust you see on a kettle element or a showerhead. Inside an appliance the same crust coats heating elements, sensors, valves and spray arms, so parts work harder and wear out sooner.

Dishwashers: cloudy glasses and weaker washing

Dishwashers feel hard water first. Scale coats the heating element and the holes in the spray arms, and minerals left on the dishes show up as a white film.

• A white film on glasses and on the inside of the door
• Spray arms with blocked holes
• Dishes that come out less clean than they used to
• Cycles that run longer as the heater works through scale

Rinse aid helps glasses dry without spots, and a dishwasher cleaner every month or two dissolves early scale. Some European-designed dishwashers have a water-hardness setting, and a few have a built-in softener that uses dishwasher salt; if yours does, set it for moderately hard water as the manual describes. Our dishwasher repair page covers the faults that need a technician.

Washing machines: detergent, scale and inlet screens

Hard water makes detergent less effective, so clothes can feel stiff and colours fade faster. Front-load washers that heat their own water can build scale on the heating element, and the small mesh screens where the hoses connect collect mineral grit over time, slowing the fill. A slow fill or a fill error code is often those screens.

Use the right amount of HE detergent (more doesn’t help with hard water, it just adds residue), run a monthly drum-clean cycle, and check the inlet screens once a year. If a fill or drain code keeps coming back, see washer repair.

Refrigerators: ice makers and water dispensers

A fridge doesn’t heat water, but its filter, inlet valve and ice maker still deal with the minerals. A filter past its date lets more through, ice comes out cloudy, and a restricted inlet valve can slow the dispenser or leave the ice maker making small, hollow cubes.

Replace the water filter on the schedule in your manual (for many models, about every six months), and if the dispenser slows or the ice maker stops, check the filter first. Our refrigerator repair page covers ice maker and valve repairs.

Kettles and coffee makers: your early warning

Small appliances show scale fastest, which makes them a useful signal. If your kettle needs descaling every few weeks, your dishwasher and washer are dealing with the same minerals, and it’s a good moment to run their cleaning cycles too.

Is a water softener worth it?

A softener removes the calcium and magnesium, which protects every appliance at once. Peel Region points out that softeners replace the hardness with sodium, so if anyone in the home is watching their sodium intake, consider keeping a separate unsoftened tap for drinking water. At around 7 grains per gallon, rinse aid, the right detergent dose and regular cleaning cycles go a long way even without one.

When scale has turned into a repair

• The dishwasher stops heating or shows a heating error
• The washer still fills slowly after you’ve cleaned the inlet screens
• The ice maker stops, or the dispenser barely flows with a new filter
• Spray arms stay blocked after cleaning

These usually mean a heating element, inlet valve or sensor has failed. A technician tests the part and gives you a written price before any work starts. For homes across the city, see our appliance repair in Mississauga page.

Frequently Asked Questions