How to avoid limescale on your dishes

Limescale is one of the things you need to be aware of when using a professional dishwasher. When the water is heated again and again, limescale and minerals from the water can settle in the machine and affect both components and washing results.

In this article, we look at why water treatment is used with industrial dishwashers, what hard water means in practice, and what the difference is between softening, partial desalination and total desalination.

Why does hard water cause problems in a dishwasher?

Water naturally contains various minerals. The amount varies depending on where in Denmark the water comes from, and the hardness of the water is related to, among other things, the calcium and magnesium content.

When water is used in a dishwasher and heated, limescale deposits can form. Over time, the limescale can settle on heating elements and other parts that come into contact with the water.

The problem is therefore not only the visible white limescale stains on glass and dishes. Limescale can also accumulate inside the machine itself.

What does limescale do to an industrial dishwasher?

In a professional dishwasher, water is heated many times during the working day. Therefore, limescale can be particularly relevant in areas with hard water.

Deposits can, among other things, occur on components that heat or conduct water through the machine. Over time, this can lead to the need for descaling and additional maintenance.

Water treatment is therefore used primarily to reduce the problems that the mineral content of the water can otherwise cause in the machine.

Why do limescale stains appear on glasses and tableware?

If water with a high mineral content is left on a glass and then evaporates, the minerals can remain on the surface. This is one of the reasons for the white spots or streaks that you may experience after washing dishes.

The problem is particularly visible on glasses, cutlery and dark tableware, where even small deposits can be evident.

Therefore, the water quality can have an impact on how much polishing is necessary after washing.

What does water hardness mean?

The hardness of the water basically tells you something about the amount of calcium and magnesium compounds in the water. The harder the water, the greater the risk of limescale deposits.

This also means that the need for water treatment is not necessarily the same throughout Denmark.

If you want to know the conditions at a specific address, you can check the water hardness at the local waterworks or water supply company.

In some cases, our technicians will take a water sample before setting up the machine in question.

What is the difference between softening and desalination?

There are several ways to treat water, and they do not necessarily give the same result.

Softened water

Softening reduces the substances in the water that cause hardness and limescale problems. The purpose is mainly to protect the machine from limescale. It is typically an AK filter that we put on a dishwasher when the need is normal.

Other dissolved salts and minerals may still be present in the water. Therefore, re-polishing may still be necessary if you want completely spotless glass and tableware.

Partially desalinated water

Partial desalination reduces both limescale-forming compounds and some of the water's other mineral content.

This provides both limescale protection for the machine and reduces the risk of visible residue on the tableware. The result can therefore be more spotless than with regular softening.

Total desalination and reverse osmosis

If you want to remove almost all of the dissolved minerals and salts from the water, more extensive water treatment such as reverse osmosis can be used.

It is used, among other things, when high demands are placed on the result for glass and cutlery. When very few minerals remain in the water, there is correspondingly less material that can remain on the surface when the water evaporates.

Is water treatment only relevant because of limescale?

No. Protecting the dishwasher itself is important, but the water quality can also have an impact on the final result.

This is especially true in places with a lot of glass, where re-polishing can take a lot of time. The fewer minerals left on the glass after drying, the less re-polishing may be necessary.

Therefore, two kitchens with the same dishwasher may well have different needs. A restaurant that primarily washes dishes and kitchenware may have different priorities than a bar or restaurant with a large number of wine glasses.

Do all industrial dishwashers need external water treatment?

Not necessarily. Some professional dishwashers may be equipped with internal water treatment or descaling, while others are installed together with an external solution.

This depends on both the machine and the water quality at the installation site. Therefore, it is worth checking the manufacturer's requirements and recommendations for the specific model.

This is especially important in connection with warranty and maintenance, as limescale damage is not necessarily treated in the same way as normal technical faults.

How do you know if the water treatment is still working?

A water filter or other water treatment system does not necessarily have unlimited capacity. How long it lasts depends on the type, the hardness of the water and how much water passes through the system, among other things.

A filter that is suitable for a kitchen with limited washing-up may therefore have a completely different lifespan in a busy restaurant.

It is important to follow the manufacturer's instructions for replacement, regeneration and service. Otherwise, the water treatment may lose its effect, even if it is still physically in front of the machine.

Water treatment is part of the overall installation

Water treatment should therefore not be considered in isolation from the dishwasher. The hardness of the water, the machine's water consumption and the requirements for the washing result are all related.

If you are about to buy a new machine, you can see our industrial dishwashers. For each individual installation, the need for water treatment should be assessed together with the machine's other requirements for water, electricity and drainage.