Common Dishwasher Problems: What the Symptoms Mean

Modern Dishwashers Are Complex — But Most Problems Are Predictable

Today's high-end dishwashers (Miele, Bosch, Thermador, Asko) pack sophisticated wash systems, sensors, and electronics into a tight space. When something goes wrong, the symptom usually points directly to a specific component. Here's what the most common problems mean.

Dishes Aren't Getting Clean

This is the number-one complaint. The most common causes:

• Clogged spray arms: The tiny holes in the spray arms get blocked by hard water deposits and food debris. Remove and rinse them monthly.
• Worn or clogged filter: Most modern dishwashers have a removable filter at the bottom of the tub. A clogged filter recirculates dirty water. Clean it every 1–2 months.
• Low water temperature: Dishwashers need 120°F water to clean effectively. If your water heater is set too low, or the heating element is failing, dishes won't come clean.
• Wash pump issues: A failing wash pump reduces water pressure to the spray arms, resulting in poor cleaning.

Water Left Standing at the Bottom

Standing water after a cycle indicates a drain issue. Check these in order:

1. Clean the filter — food debris blocking the filter is the most common cause
2. Check for a kinked drain hose
3. Inspect the garbage disposal knockout plug if your dishwasher is newly installed
4. If none of the above, the drain pump likely needs replacement

Dishwasher Won't Start

Before calling for service, check:

• Door latch fully engaged? Most dishwashers won't run with a partially latched door.
• Control lock activated? Many models have a child lock that disables the controls.
• Circuit breaker tripped?

If all of the above check out, the issue is likely the door latch switch, control board, or thermal fuse — all require professional diagnosis.

Dishwasher Leaking

Leaks are one of the more urgent dishwasher problems — water damage to floors and cabinets is expensive. Common leak sources:

• Door gasket: The rubber seal around the door dries out and cracks. Replacement is straightforward.
• Float switch stuck: The float prevents overfilling. If stuck down, the dishwasher may overfill and leak.
• Pump seal or hose: Internal leaks that appear under the unit typically involve pump seals or hose connections.

Unusual Noises During the Wash Cycle

• Rattling: Loose items or spray arm hitting a tall dish — load adjustment usually fixes this
• Grinding: Debris in the pump or a failing pump motor
• Humming: Normal during fill and drain; unusually loud humming may indicate pump strain

When to Call a Professional

Self-service fixes like cleaning filters and spray arms are valuable maintenance steps. But when problems involve the pump, control board, heating element, or internal leaks, professional diagnosis prevents minor issues from becoming major water damage events. We carry Bosch, Miele, and Thermador parts on our service vans for same-day repairs.

---

Published by the Turn Appliance Repair team · Serving Burbank, Glendale, Pasadena, Beverly Hills, and all of Greater Los Angeles · (818) 968‑2468