Dishwasher Not Cleaning Dishes? 7 Reasons & How to Fix Each
A dishwasher that doesn't clean is almost never broken — it's almost always neglected. Utah's hard water is particularly tough on dishwashers, and most owners don't know about half of these issues. Work through this list in order: by the time you're done, you'll either have a fixed dishwasher or a very clear idea of what to tell the tech.
Maintenance recommendations
1. Clean the filter (the #1 culprit)
Twist out the cylindrical filter at the bottom of the tub — rinse it under hot water and scrub with a brush. Most people have never done this. A clogged filter recirculates dirty water onto your dishes.
2. Check water temperature
Dishwashers need water at 120°F minimum to dissolve detergent and rinse aid. Run the hot tap at the sink for 30 seconds before starting the dishwasher so the hot water is already at the pipe.
3. Inspect the spray arms
Pop off the upper and lower spray arms. Hold them up to the light — clogged spray holes mean water doesn't reach the dishes. Clear each hole with a toothpick.
4. Don't pre-rinse
Counterintuitive but true: modern enzymatic detergents need food residue to activate. Pre-rinsing strips that residue and the detergent doesn't engage. Scrape, then load.
5. Use a rinse aid
In hard-water areas like Magna and the Salt Lake Valley, rinse aid is mandatory — not optional. Without it, glasses come out cloudy and dishes don't dry. Keep the dispenser full.
6. Run a cleaning cycle monthly
A cup of white vinegar on the top rack run through a hot empty cycle dissolves the limescale that hard water leaves behind. Follow up with a cup of baking soda on the bottom on a short cycle.
7. Check the water inlet valve
If you suspect the dishwasher isn't getting enough water, open the door mid-cycle: you should see water pooled at the bottom. If it's dry, the inlet valve may be failing — that's a service call.
Most common failures
Failed circulation pump
If you've cleaned everything and dishes still come out dirty, the pump that sprays water through the arms may be weak. Listen during a cycle: a healthy dishwasher sounds like steady rushing water, not just a faint hum.
Worn spray arm bearings
Spin each spray arm by hand. They should rotate freely and smoothly. If they wobble or stick, the bearing or seal is worn and water isn't being sprayed evenly.
Stuck or failed detergent dispenser
Open the door mid-cycle. If the detergent compartment is still closed and full, the dispenser latch has failed. Common on Bosch and KitchenAid units 5+ years old.
When to call a technician
If you've worked through the list and dishes are still coming out gritty or cloudy, give us a call. Most dishwasher cleaning failures are quick diagnoses — and we'll tell you straight if it's worth fixing or replacing.