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Dishwashers are one of the appliances in our kitchens that we depend on the most. They handle washing crockery and cutlery like a pro and they can be super water and energy efficient, saving us a lot of time and hassles.
But when your dishwasher stops working properly, you may start wondering what could be causing the problem. One common issue is that the dishwasher doesn’t clean the top rack of dishes effectively, causing you to wonder what the possible causes could be.
In this article, we aim to help you address this problem by exploring some of the most common reasons why your dishwasher isn’t cleaning the top rack and cover some preventative maintenance tips to help you keep your appliance in good working order. Let’s get started.
Dishwasher Not Cleaning Upper Rack: Common Reasons
There are several common reasons why your dishwasher is not cleaning the upper rack. While the bottom rack’s dishes come out clean, the ones at the top do not. This is cause for concern, but some of the diagnostics you can perform are quite easy and simple to do yourself. Take a look at things you should be paying attention to as you aim to get to the bottom of this issue.
Not enough water pressure
Insufficient water pressure can prevent the spray arms from rotating properly and distributing water effectively. This can result from a kinked water supply line, a partially closed shut-off valve or low household water pressure.
In order to check for adequate water pressure, you need to switch off your dishwasher and try to locate the water inlet valve. If you aren’t sure where this is, consider consulting the owner’s manual. For more information on water inlet valve issues and other potential causes, check out our article Why Is My Dishwasher Not Filling with Water. Once you have located it, make sure that it is opened fully so that more water can get in, thus boosting the water pressure and ensuring a better cleaning cycle.
Insufficient Hot Water Supply
One common reason your dishwasher may struggle to clean the top rack effectively is an insufficient hot water supply. Dishwashers typically require water heated to a minimum temperature of 120°F (49°C) for optimal performance. If the water entering your dishwasher isn’t hot enough, it can lead to poor cleaning results, especially for items on the upper rack. To ensure that your dishwasher operates at peak efficiency, check your water heater settings and run the hot water tap in the sink before starting a cycle to guarantee proper water temperatures are reached.
Clogged upper spray arms
Upper spray arms can become clogged with food particles, mineral deposits, or other debris. When the holes in the spray arms are blocked, water cannot be sprayed with enough force to clean dishes thoroughly.
To resolve this issue, you will need to switch off the dishwasher completely at the source of power. You’ll then want to remove the spray arm and see if any of the holes are full of gunk. Another quick test you can do is to simply try to rotate the upper spray arms to see if they move around smoothly. If they are blocked by a large object, like a pot for example, this obstruction could be the reason for your dishwasher not getting your top rack clean.
Improper loading of dishes
Overloading the top rack or placing items incorrectly can obstruct the spray arms and prevent water from reaching all surfaces. Large items may block smaller ones, leading to inadequate cleaning.
In order to ensure proper loading, you should consult your owner’s manual. However, as a general rule of thumb, you should always place the larger and heavier items at the bottom. Dishes should always face down and there should be sufficient space between each item in the dishwasher so that enough water gets in between them for thorough cleaning.
Malfunctioning detergent dispenser
If the detergent dispenser does not open properly or releases detergent too early or too late in the cycle, the dishes on the top rack may not get enough cleaning agents to remove food debris.
In such cases, you will want to call in a professional to take care of the issue because it involves more complex troubleshooting and is the recommended route to take.
Dishwasher filter and drain issues
A clogged dishwasher filter can restrict water flow, reducing the effectiveness of the spray arms. Similarly, a blocked drain can cause dirty water to recirculate, preventing proper cleaning.
You’ll first want to identify where your filter is and once you’ve done so, give it a good emptying and cleaning. Make sure the dishwasher is completely disconnected from its power source before you do this. Ensuring proper drainage also involves checking the connecting pipes and seeing whether there are any kinks in them.
Worn out or broken dishwasher
Parts components such as the pump, motor or wash impeller can wear out or break over time. These parts are essential for maintaining adequate water pressure and spray patterns. If they fail, the dishwasher’s performance will suffer.
If you have checked all of the above potential causes and you’re still stuck with a faulty dishwasher, the recommended route of action is to get in touch with and call in a professional. They will be able to accurately diagnose and repair the fault, while bringing the necessary spare parts with them to ensure you aren’t kept waiting.
Preventative Maintenance Tips to Keep Your Dishwasher Top Rack Clean
Wondering how to extend the longevity of your dishwasher and keep it working optimally? The following tips from our engineers can help you.
- Follow regular cleaning routines: Read your owner’s manual and establish how often you should clean your dishwasher. Often, the frequency will be determined by the number of cycles you run and how heavy your loads are. Additionally, consider using baking soda to deodorise and cleanse your dishwasher during your routine maintenance, as it can effectively eliminate odors and improve overall performance.
- Use proper detergents and rinse aids: Always follow the manufacturer’s guidelines on which detergent and rinse aid you should use for your model of dishwasher. Not all detergents are created equal and some may do more harm than good by leaving excess residue in your detergent dispenser, which can then spread to the rest of the dishwasher or clog up your dispenser.
- Schedule professional maintenance: Keeping your dishwasher running in good condition for a long time is possible with regular and professional maintenance. If you want to take some preventative steps to ensure your appliance continues to function in great working order, then calling a Domex professional is always a good idea at any time.
Frequently Asked Questions (FAQs)
How often should I clean the dishwasher filter?
The cleaning frequency of your dishwasher’s filter will depend on whether you wash, scrape and rinse your dishes before a wash. For washed dishes, clean the filter once annually. The same applies for scraping and rinsing before loading. Bi-annual cleaning of the filter should be performed if you only scrape before loading. And if you neither scrape nor rinse, then it’s advisable to clean the filter every two months.
Can hard water affect my dishwasher’s performance?
Yes, hard water can have an impact on your dishwasher’s performance when mineral deposits clog your pipes, filters and spray arms.
What is the best way to load the top rack?
Always place drinking implements face down along the sides. Meanwhile, small bowls and plates should be placed facing downward and at an angle toward the centre of the dishwasher.
Need Professional Help? Contact Domex for Expert Dishwasher Repairs
If in doubt or you simply don’t have the time to carry out a DIY inspection, you can always rest assured that the engineers at Domex can come to the rescue in any Bosch, Whirlpool, Samsung, Beko, LG, or other brand dishwasher-related emergency or situation you may have.
Our dishwasher repair service is backed by a 12-month guarantee on faults fixed and/or spare parts fitted, giving you greater confidence and peace of mind. With a Domex engineer at your side, you truly can rest easy knowing your appliance is in excellent hands. Enjoy quality workmanship with us and take advantage of affordable prices that are budget-friendly.