Why You Should Never Leave Water In Your Kettle

by Jay | Updated on October 22nd, 2022

When we boil water, we usually need to use it immediately because it will be used for cooking and drinking.

In this article, we’ll learn whether leaving water in a kettle is safe.

Should you always empty the water kettle?

Yes, you should always empty your kettle’s water is the simplest answer to this question. The main reason for this is scale formation. Limescales accumulate in the kettle if any water is left inside.

For those who don’t know what timescales are, they are the white and chalky buildups that form inside and outside of your water kettle as a result of Calcium and Magnesium particles found in hard or tap water.

It’s important to remove limescale because:

  • The taste of boiled water is altered by limescale. Because the limescale alters the quality of the boiled water, coffee and tea drinks taste slightly off and unusual.
  • Limescale reduces the lifespan and efficiency of the kettle. In addition, it reduces the kettle’s ability to heat water and increases the likelihood that the kettle will need to be replaced in the long run.
  • I’m sure you do not want to look at limescale floating in cups of coffee or tea.

Is limescale in my kettle bad for my health?

Limescale is caused by the high concentration of calcium in the hard water we drink, so consuming some from your kettle or coffee maker will not harm you.

Kidney stones form when a substance in the body, such as calcium, ammonia, or cystine, accumulates.

However, there is no evidence that drinking hard water increases your risk of kidney stones. On the other hand, you’re more likely to develop them if you don’t drink enough water, so keep your kettle in good working order and brew up!

Most mineral waters sold in stores contain minerals such as magnesium and calcium that are beneficial to the body. Natural spring waters generally have the right balance of these minerals to keep us healthy!

On the other hand, limescale can cause your skin to dry out. So, if you live in a hard water area, remember to use a good hand and body cream regularly.

What causes kettle limescale?

Hard water, which is high in minerals like calcium and magnesium, causes limescale in your kettle. Try a quick soap lather test at home to see if you have hard water. Fill a water bottle halfway with water and a small amount of soap. Shake the bottle.

If your water is frothy and bubbly, it is likely soft. On the other hand, if your water is cloudy, milky, and has dull bubbles, you most likely have hard water. If you suspect you have hard water, you can purchase a more advanced water test kit at any DIY store to determine the exact hardness of your water.

How to remove limescale?

Cleaning limescale from the kettle is not a difficult task. You can use a store-bought limescale remover to remove the limescale from the kettle.

It is very effective, but remember that limescale removers have the minor side effect of leaving a soapy taste in the water and are quite expensive in the long run.

Alternatively, this can be accomplished with the most basic of tools: an acid solution. Fill the kettle halfway with water and halfway with acid (preferably lemon juice, vinegar, or baking soda) and leave it to soak for up to an hour. This should loosen the limescales’ grip on the kettle.

After an hour, you should boil it, empty it, and repeat the process (but with water only) before thoroughly rinsing the kettle.

To keep your kettle running smoothly, perform the cleaning and descaling process weekly or monthly. While the preparation time may be longer than purchasing a store-bought limescale remover, you will be able to save more money because you will not be using expensive cleaning materials.

How to stop kettle limescale?

If you’ve already noticed residue forming and want to remove kettle limescale, there are some quick (but temporary) fixes.

First, you can clean your kettle scale with vinegar by boiling it with a solution of 1/2 vinegar and 1/2 water and then scrubbing the areas with kettle limescale. You can also use citric acid, which is found in lime juice, or baking soda. However, remember that descaling your kettle will not prevent limescale from reappearing.

There is also a common misconception that bottled water can help prevent limescale – this is untrue because bottled water still contains minerals. However, the environmental impact of plastic bottles must also be considered, so having soft water is the best long-term solution.

How to prevent kettle limescale?

If you want a more convenient, long-term solution, consider purchasing a water softener that converts hard water to soft water by removing hard minerals from the water and reducing build-up. In addition, because hard water often has an unpleasant metallic taste, soft water improves the taste of your drinks – a bonus!

Do water kettles kill bacteria?

You might ask why you need to clean a kettle when you can boil the water; wouldn’t that kill all the bacteria?

The kettle cannot kill bacteria on its own. The bacteria are destroyed by boiling the water inside the kettle. Any unwanted microorganisms, such as bacteria and parasites, are killed and expelled by bringing the water within the kettle to a boil at 100 degrees Celsius (212 degrees Fahrenheit).

But, can any bacteria survive boiling water?

Although certain bacterial spores not usually associated with water-borne disease (e.g., clostridium and bacillus spores) can survive boiling conditions, research shows that water-borne pathogens are inactivated or killed at temperatures below boiling (212°F or 100°C). Therefore, it is best to use purified, filtered water instead of tap water.

Why is it not good to reboil water?

The quick answer is NO. Never re-boil the water left in your kettle. It is preferable to empty the kettle, refill it, and heat a new batch rather than re-heating already heated water.

When it is re-heated, however, the dissolved gases and minerals that have undergone a chemical transformation accumulate and become significantly more toxic.

“The contaminants in the water get concentrated, stuff like nitrates, arsenic, and fluoride,” said Julie Harrison of Improve Your Health. “Each time you reboil the bath, they become more concentrated, and you don’t want them in your body.”

Nitrates degrade into carcinogenic nitrosamines. These chemicals have been related to diseases such as leukemia, non-Hodgkin lymphoma, and other forms of cancer.

Second, you do not want to reboil your kettle water because it is many coffee and tea lovers’ worst nightmare. To begin with, boiling water has a bland taste, and reheating it makes it taste even worse. If you brew tea or coffee with re-heated water, the result is a very weak tea. If you have to reheat your water, you won’t be able to enjoy the quality of your brewed beverage.

There is only one circumstance under which you can re-heat water: when you use distilled or deionized water, which has already been drained of any gases or elements found in ordinary water. Do not re-boil water from the faucet because it contains the elements above, which can become concentrated with frequent re-heating.


Water re-boiling does more damage than healthy. It makes the already flat-tasting boiled water taste much worse and raises the risk of health issues due to the over-concentration of some chemicals in the water. Therefore, re-boiling water is never a good idea unless you use deionized or purified water.


Jay is a health and wellness enthusiast with expertise in water quality and nutrition. As a knowledgeable advocate for holistic well-being, Jay successfully manages Type 2 Diabetes through informed lifestyle choices. Committed to sharing reliable and authoritative insights, Jay combines firsthand experience with a passion for enhancing health."