5 reasons your dishwasher isn't cleaning dishes properly

A poorly performing dishwasher is often the result of simple, easily fixable mistakes rather than a technical malfunction. From incorrect dish placement to a clogged filter, small oversights can have a big impact on wash results. Checking these common errors before calling a technician could save time and money.

If your dishwasher keeps leaving dishes grimy or spotted, the culprit is likely something far simpler than a broken machine. Many users unknowingly make a handful of recurring mistakes that significantly reduce cleaning performance — and most of them are easy to fix without professional help.

Wrong dish placement

One of the most common errors is loading dishes incorrectly. Bowls and cups placed right-side up collect standing water rather than draining, while oversized items blocking the spray arms prevent water from reaching other dishes. Following the manufacturer's loading guide for your specific model can make a noticeable difference immediately.

Neglected filter and spray arms

A dirty or clogged filter is another frequent offender. Food particles and grease accumulate over time, reducing water flow and leaving residue on dishes. Most dishwasher filters can be removed and rinsed under running water in just a few minutes. Similarly, the spray arm holes can become blocked with mineral deposits or food debris — a quick rinse or gentle cleaning with a toothpick restores their function.

Wrong programme and detergent

Using the wrong wash cycle for the load type — for instance, running a quick programme on heavily soiled pots — often leads to disappointing results. Equally, using too little or poor-quality detergent, or placing the tablet in the wrong compartment, reduces effectiveness. Checking that the rinse aid dispenser is filled also helps achieve spot-free, dry results.

Hard water and machine maintenance

In areas with hard water, limescale builds up inside the machine over time, affecting both the heating element and spray performance. Running a dedicated dishwasher cleaning cycle or using a descaling product monthly keeps the interior in good condition. Addressing these simple maintenance steps regularly is far cheaper than an unnecessary service call.