July 11th, 2023 by Shauna Hammond

Dishwashers are a big investment, but when you have a large family or a lot of dishes to go through then they quickly become an important part of your cleaning routine. So, nothing is more frustrating than when you go to unload the dishes only to find that the glasses are streaky, your mugs still have coffee stains and your plates still have food on them! So why is your dishwasher not cleaning correctly? Is it time for a replacement? Fortunately, it probably isn’t broken so you don’t need to worry about any costly replacements. In this blog we will look at some common causes for dishwashers not cleaning correctly and how you can rectify the issue.

Too Much or Too Little Detergent

Problems with detergent, whether too much, too little or just the wrong kind can lead to dishwashers not correctly cleaning loads. If you are using too much detergent you may notice that glasses becoming streaky or you may feel a slimy residue on the surface of some dishes too. On the other side if you don’t have enough detergent then essentially your dishes are only being rinsed with warm water so they will not be effectively cleaned, so more stubborn stains such as coffee, tea or sauces may remain. So, make sure to follow the manufacturer’s instructions to ensure that you are using the correct amount of detergent for each load.

Likewise, if you fail to re-fill the rinse aid in your dishwasher this can also lead to glasses and other dishes not looking clean and shiny, it is also possible that it can lead to scratching too which will lead dishes to look dull and unclean even if they have been thoroughly washed. So be sure to check the amount of rinse aid before each wash to ensure that there is enough.

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Improper Loading

One of the most common problems for a dishwasher not correctly cleaning your dishes can simply be a cause of it not being loaded correctly. It can be tempting to just throw all the dishes in, in any way that you can in order to fit as much as possible into one load. Unfortunately, it’s not quite that simple and if you don’t load up your dishwasher correctly the water and detergent can’t do their job correctly which can result in dishes coming out of your machine looking like they have not been cleaned correctly.

When loading your dishwasher, you should place dishes between tines and not over them, have them face the centre at a downward angle, and don’t have dishes overlap one another as this will prevent the soap and water from getting to every part of the dishes. As for cutlery ideally, keep the different types together, knives and spoons should be faced down while forks should be faced upward for better cleaning.

Obstruction of Arm

If the above does not solve your problem, it may be time to look into the dishwasher itself. Check the arms of the dishwasher to ensure there is nothing blocking or obstructing their movement. If these arms are not able to spin freely then this will stop the water from correctly circulating around the machine and therefore not cleaning your dishes.

If you notice the arms are not moving correctly, then remove whatever obstruction may be causing this and if you are unable to see an obvious obstruction then contact a technician and they will be able to check for any other underlying issues that may be causing the problem – don’t try taking your own dishwasher apart unless you are 100% confident as you risk voiding your warranty or causing more damage. Once the arms are able to freely move again hopefully the problem should be resolved and you can get back to brilliantly clean dishes.

Limescale Build-Up and Other Maintenance Issues

Failure to correctly maintain and clean your dishwasher can also result in dishes not being cleaned correctly. While it may be tempting to think that our dishwashers are self-cleaning after all they use water and detergent right? Well not quite. You need to take the time to clean your dishwasher after all food debris can become trapped in the filters and soap scum and also build up on the inside – these contaminants then remain in your dishwasher when it completes the next cycle transferring the dirt and bacteria on to your plates. Conduct a deep clean on your dishwasher every week and try to remember to empty and rinse the filter after every use to remove any food particles that may have gotten stuck.

Similarly, it is important to use a descaling product on your dishwasher, particularly if you live in a hard water area, at least once every 3 months and it is also important to ensure that you keep on top of re-filling your dishwasher salt as this will also work to prevent the build-up of limescale. Failing to keep on top of limescale treatment can result in limescale deposits from building up on the heating elements and on the jets. Limescale in these areas can result in the water not reaching full temperature which makes it more difficult to remove dirt it can also reduce the water pressure or cause blockages in some of the jets drastically reducing the amount of water used in cycles and reducing efficiency. If left untreated limescale may also result in a complete breakdown of your dishwasher which can lead to some very pricey replacements.

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Bad Odours

Sometimes you may notice that although your dishes appear to be coming out of the dishwasher clean, they don’t smell quite as fresh as you would like, or perhaps you have noticed a lingering odour when you open your dishwasher. It’s not pleasant to have any room filled with bad odours especially one where you prepared food, and you certainly don’t want to be taking a drink from a mug or glass and be greeted with a foul smell.

This may be caused by a build-up of bacteria within your dishwasher, this may be located in the pipes or pump making it harder to reach with your usual clean. Not to worry, however, this can usually be treated fairly easily by using by pouring white vinegar in your machines, leaving it for around 30 mins to an hour before then running and cleaning cycle, this should hopefully remove the source of the bad odour and will allow the detergent to better do its job so you don’t have to deal with a smelly dishwasher or dishes.

Hopefully, this article has helped you understand why your dishwasher is not cleaning correctly and how to resolve this issue. Generally, it falls to proper cleaning and maintenance, this is the best way to ensure that your dishwasher keeps working at its best and keeping your dishes clean. However, if after following these steps, you notice the issue persists it may be time to contact a professional as there may be a larger underlying issue that needs addressing.