Descaling a dishwasher takes three moves: clean out the filter, run an empty hot cycle with a dishwasher descaler or cleaner, then wipe down the door gasket and edges. Chalky white film on the tub, racks or glassware is your cue, and homes with hard water should put it on a regular schedule.
Time: about 15 minutes of work plus one cycle · Difficulty: Easy · You'll need: a dishwasher descaler or cleaner product, a soft cloth, a soft brush, rubber gloves
Before you start
- •Read the descaler label and your dishwasher manual first. Some manufacturers caution against certain products, including frequent use of vinegar, so follow what your manual allows.
- •Never mix cleaners. Combining products, especially anything with bleach, can release harmful fumes.
- •Wear gloves when handling descaling chemicals.
- •Empty the dishwasher completely.
Steps
Step 1 — Confirm it's scale
Mineral scale looks white or chalky and feels gritty, and it often concentrates on the tub floor, around the heating element (on models with an exposed one) and on the racks. Cloudy glasses that wipe clean with a little vinegar on a cloth also point to minerals.
Step 2 — Clean the filter first
A clogged filter traps scale flakes and food that will undo your work, so pull it and rinse it before descaling. See how to clean a dishwasher filter for the full process.
Step 3 — Add the descaler
Place the descaler exactly where its label says, which may be the detergent cup, the tub floor or a container on the top rack. Use the amount listed and nothing more.
Step 4 — Run the hottest empty cycle
Select the hottest normal or heavy cycle with the dishwasher empty. Some models have a dedicated clean or sanitize cycle, and that's a good choice if the descaler instructions allow it.
Step 5 — Wipe the edges and gasket
The door edges, the bottom lip of the door and the gasket never get a full spray. Wipe them with a damp cloth and a little dish soap, and brush scale off the lower door hinge area.
Step 6 — Fill the rinse aid
Rinse aid helps water sheet off dishes so minerals don't dry into spots. Fill the dispenser to the line and wipe up any spill, which can cause excess suds.
Step 7 — Check the result
Look over the tub and racks after the cycle. Heavy buildup sometimes needs a second treatment.
Didn't fix it?
If film comes back within a week or two, your water is likely very hard, and you may want to look at whole-home water treatment with a plumber. Dishes that stay cloudy even after descaling can also mean etching, which is permanent wear on the glass itself and won't wash off. If the dishwasher stops heating, fills slowly or shows an error after scale buildup, have our dishwasher repair team check the heating and inlet parts.
New Jersey tip
Water hardness varies a lot from town to town in New Jersey and depends on your supplier, and many homes in the state have hard water. Your water utility's annual water quality report often lists hardness. If your home is on a private well, a simple hardness test strip from a hardware store will tell you where you stand.
From Kevin: On hard water I see scale collecting at the bottom of the door and around the heating element first. Catching it early with a routine descale is far easier than chipping off years of buildup.
Talk to a technician: ProFix NJ, (973) 718-9373.