Dishwasher descaling – A guide

Once you spend the money on a good dishwasher, you naturally want it to last as long as possible. In addition to the regular refilling of dishwasher salt and rinse aid, you should also decalcify the dishwasher regularly. You should pay attention to a few points, which we would like to present in the following article.

What are lime deposits?

Lime is also known as calcium carbonate and consists of calcium, oxygen and carbon. Since the sources of drinking water are also located in rock layers, it absorbs calcium and magnesium carbonate when flowing through it. In the household, limescale forms where water has been heated, e.g. on faucets, in pots or even in the dishwasher. Lime deposits are caused by so-called “hard” water, i.e. water with a high calcium carbonate content. This substance, which is dissolved in water, is a hardener. When the water evaporates, the lime remains, mostly visible as white spots and streaks.

How hard is my water?

How “hard” the water is varies greatly from region to region. Before descaling, however, you should find out what degree of hardness the water has in your region. You can obtain this information from the local waterworks. In most cases, the data can also be found on the respective website.

Why you should decalcify the dishwasher regularly?

It becomes problematic when limescale builds up in pipes or in places that are important for the operation of the dishwasher. This ultimately severely impairs the dishwashing performance and the detergent (whether dishwasher tabs or powder or liquid detergent) steadily loses its effectiveness. In addition, it takes longer for the water to heat up to the necessary temperature or it does not reach this temperature at all. This is noticeable at the latest with the higher expenses for energy costs.

If limescale deposits are ignored over a longer period of time, there is a risk that the entire appliance will fail due to damage to materials such as important seals. In particularly severe cases, cracks may appear in the piping, also known as corrosion. This may even lead to water damage in the house and apartment. This is also why every dishwasher has a water softening system to maintain the dishwashing performance of the machine.

The reasons briefly summarized:

  • For a permanently optimal dishwashing result
  • For a longer life of your dishwasher
  • For better energy efficiency and lower power consumption
  • For consistently high wash temperatures
  • For more hygiene when washing dishes
  • To prevent water damage, as calcification can cause plastic parts to become porous.

How to decalcify the dishwasher?

Descaling the dishwasher with descaler

There are various ways to get rid of lime deposits. In stores you can find a wide range of products produced specifically for this purpose: The so-called descalers. In liquid form, these can be used to treat externally visible areas or are sometimes hung in the dishwasher’s crockery basket. Likewise, they are available in pressed tabs that are simply placed in the machine for a rinse cycle, where they dissolve and remove the limescale.

A little guide – descaling the dishwasher with descaler

  • Step 1: Clear all dishes from the dishwasher.
  • Step 2: Clean door seals, strainer inserts and spray arms with warm water and some dishwashing detergent
  • 3rd step: fill in descaler according to the instructions for use
  • 4th step: Start rinse cycle at high temperature (min. 60°C)
  • Step 5: Remove possible lime and dirt residues after the rinsing cycle with a soft sponge and some liquid descaler.
Important: You should always follow the instructions on the packaging. In most cases, a wash cycle at around 60°C is recommended. In addition, you should never use abrasive cleaners or metal sponges in the dishwasher.

Descaling the dishwasher with vinegar or citric acid

If you prefer to use natural remedies against limescale, you should opt for citric acid or vinegar essence.

Descaling with vinegar

  • Use white clear vinegar.
  • In a small bowl, mix 1/4 liter of warm water and a dash of vinegar well, then use a soft sponge to wipe out the inside of the dishwasher.
  • Close the door and start a dishwashing program at the highest possible temperature and without prewashing.
  • Once the water in the dishwasher is heated, briefly open the door and pour in a cup of vinegar. Let this soak in for about 1 hour and then run the dishwasher through to the end.

Descaling with citric acid

  • Mix 10 tablespoons of citric acid with 2 liters of cold water.
  • Start a standard low temperature rinse cycle.
  • When the machine has run full of water, briefly open the door again, pour in the acid mixture and let it soak for about 1 hour. Then run the program to completion.

It is important for all processes that the dishwasher is empty and the program is started without prewashing.

How often should the dishwasher be descaled?

If you’re wondering how often you should descale your dishwasher, the answer is, as it often is, “It depends.” “On what?”

  • On the hardness of your water and
  • How often the dishwasher is in use.

The best way to tell if your dishwasher needs to be descaled is by the condition of the heating element. If you can’t see any limescale deposits there, the rest of the machine is usually also largely free of limescale, because it’s precisely where water is heated strongly that limescale forms more quickly than elsewhere.

Note: As a rule, descaling the dishwasher is necessary no more than 1-2 times a year. If you have hard water in your area and use the dishwasher daily, 1x a year will also be enough, but if you still discover visible lime deposits, descale another time. If, on the other hand, you live in an area with soft or medium-hard water, there is sometimes no need to decalcify at all, provided of course that you always top up the dishwasher salt in good time.

Further tips for descaling dishwashers

The proper use of dishwasher salt is very important for the descaling function built into the dishwasher, otherwise more lime will be formed. So if you don’t add salt properly, the machine will calcify very quickly. Almost all dishwashers have an indicator light that shows when the dishwasher salt needs to be refilled. If your machine does not actually have an indicator, you will need to look directly inside the machine in the salt compartment to see if there is enough salt left and refill it. You can always find out how you should dose in the operating instructions.

The use of so-called multitabs can replace the dishwasher salt. However, if the water is hard to very hard, it is better to use special salt, as confirmed by Stiftung Warentest.

With modern dishwashers, it is now possible to set the water hardness in order to precisely adjust the degree of descaling. After connecting the dishwasher, this setting should also be made, whether after the new acquisition or a move. If you always adjust the setting correctly to the correct water hardness, descaling the dishwasher will rarely be necessary.

Dishwashers expert with over 10 years of experience. He writes articles and shares his knowledge on many sites. Helps you choose the best (portable, countertop, built-in) dishwashers on this site.

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