A dishwasher is one of the most convenient kitchen appliances—until it stops doing its job. There’s nothing more frustrating than unloading what should be a clean load of dishes only to find food residue, cloudy glasses, or greasy film still clinging to everything. If your dishwasher isn’t cleaning properly, it doesn’t necessarily mean the appliance is broken. Often, the issue is due to something simple and fixable. The key is identifying the cause and taking the proper steps to resolve it.

When your dishwasher fails to deliver sparkling results, the first step is to take a closer look at how you’re loading it. Incorrect loading can prevent water and detergent from reaching all the surfaces of your dishes. If you overcrowd the racks, stack plates too closely, or block the spray arms with large items, you’re likely interfering with the cleaning process. Ensure that bowls are tilted for proper drainage, glasses are securely placed to prevent tipping, and utensils are spaced sufficiently to allow water to circulate freely. Check that the spray arms can spin freely and aren’t being obstructed by tall pans or utensils sticking out of the silverware basket.

Another common issue is using the wrong type or amount of detergent. Using a low-quality detergent or an improper amount can result in underwhelming cleaning performance. Some water types, tough water, require specific formulations to break down grime effectively. If you notice a white film on your dishes or inside the appliance, mineral buildup from hard water may be affecting the cleaning power. In such cases, switching to a detergent formulated for hard water or adding a rinse aid can make a noticeable difference. Additionally, ensure the detergent compartment isn’t clogged or damaged, and that you’re not mixing detergent types (such as pods and liquid) at the same time.

The water temperature plays a crucial role in your dishwasher’s performance. If the water entering your appliance isn’t hot enough, it won’t properly dissolve the detergent or break down grease and food residue. Ideally, the water should be at least 120°F (49°C) when it enters the machine. You can test this by running the kitchen sink tap until the water reaches a comfortable temperature, then filling a cup and measuring it with a thermometer. If the temperature is too low, adjusting your water heater’s settings may resolve the issue. Some dishwashers also have internal heating elements to help boost the water temperature, but if that component fails, it may require professional repair.

Over time, food particles, grease, and soap scum can build up inside your dishwasher’s filter and spray arms. When these components become clogged, water can’t circulate effectively, and performance drops. Most dishwashers have a removable filter near the bottom of the tub. Remove it, rinse it under running water, and gently scrub away any stuck debris with a soft brush. The spray arms—typically located on the top, middle, and bottom of the dishwasher—can also be removed for cleaning. Use a toothpick or small wire to clear out any holes that appear blocked. A clean filter and spray arm system ensures that water flows freely and reaches every dish.

If your dishwasher still isn’t cleaning well after checking the basics, take a moment to examine the door gasket and interior components. A damaged or dirty gasket can prevent the door from sealing properly, allowing heat and water to escape during a cycle. Wipe the gasket down with a damp cloth and check for cracks or signs of wear. Inspect the dishwasher tub for signs of rust, standing water, or loose parts that may be affecting its performance. Water that doesn’t fully drain can stagnate and reduce effectiveness in future cycles, so ensure the drain and sump area are clear.

Don’t overlook the importance of using the right cycle for the job. Light or eco-friendly cycles may not have the intensity to tackle heavily soiled dishes. If you regularly use the quickest setting, it might not be giving your dishes enough time or pressure to get clean. For best results with tough loads, use a heavy-duty or pots-and-pans cycle. These longer, more intense cycles use higher temperatures and more water to ensure thorough cleaning. It’s also helpful to run your kitchen tap until the water gets hot before starting the dishwasher. This ensures the machine begins the wash with hot water right away.

Sometimes, the problem is with the dishwasher’s water supply itself. A kinked or clogged inlet hose or a faulty inlet valve can prevent the machine from filling properly. If you notice that your dishwasher seems to start but doesn’t sound like water is flowing in, this could be the issue. Also, low water pressure in your home’s plumbing system can hinder the appliance’s ability to clean effectively. If you’re not getting enough water into the tub, a technician may need to replace the inlet valve or diagnose plumbing problems.

Power surges, worn control boards, and faulty sensors can also reduce dishwasher performance. Modern dishwashers rely on a complex combination of electronics and sensors to monitor and adjust cycle settings. If any of these components malfunction, the machine may not perform as intended. It could skip necessary phases of the wash or misread water temperature and detergent levels. If you suspect a more technical or electrical issue, it’s best to contact a professional who can run diagnostics and determine if parts need repair or replacement.

Poor drainage is another factor that can impact cleanliness. If food and dirty water linger at the bottom of the tub after the cycle is complete, the drain pump or hose is likely clogged. A backed-up drainage system can cause residual grime to redeposit on your dishes. Listen for gurgling or humming sounds when the machine tries to drain, and look for water pooling inside after a wash. In many cases, simply removing the drain hose and flushing it out can restore proper function; however, persistent problems may require replacement of pump components.

Beyond mechanical and usage issues, regular maintenance and cleaning can keep your dishwasher performing its best. Running a cleaning cycle with a dishwasher cleaner or a cup of white vinegar can help remove built-up grease and mineral deposits from the interior of the dishwasher. Sprinkling baking soda on the floor of the tub and running a hot cycle afterward can also freshen the appliance and improve performance. Performing this type of maintenance monthly helps keep odors at bay and ensures that internal components remain unobstructed.

A final consideration is age. Dishwashers generally have a lifespan of 8 to 12 years. If your appliance is approaching or has already passed that window, it may simply be wearing out. Internal parts may degrade, heating elements can become inefficient, and electronics may become unreliable. At a certain point, replacing the unit with a newer, more energy-efficient model can be a more cost-effective option than continuing to troubleshoot and repair it.

In summary, a dishwasher that isn’t cleaning well can be frustrating, but the issue is often fixable. From something as simple as rearranging your dishes or switching detergents, to more involved tasks like clearing spray arms or replacing a faulty valve, there are many ways to restore performance. By being observant and proactive, you can identify the root cause and take action—either independently or with the assistance of a professional. With a bit of care and maintenance, your dishwasher can return to delivering the clean, sparkling results you expect.