Page last updated on 17th August 2026
Kettle running costs and maintaining your kettle
Boiling a kettle is something many of us do several times throughout the day without much thought, but how much does it cost to boil a kettle? And could overfilling it or poor maintenance be adding to your appliance’s running costs?
Small habits, such as only boiling the water you need and regularly descaling your kettle, can help improve efficiency and reduce unnecessary energy use over time.
In this guide, we’ll explore the cheapest way to boil water using an electric kettle, how limescale buildup affects kettle efficiency, and how to prevent limescale in your kettle.
How much does it cost to boil a kettle?
It usually costs just a few pence to boil a kettle, but the exact amount depends on your electricity tariff, kettle wattage and how much water you fill it with.
The fuller the kettle, the longer it will take to boil. If you’re looking for the cheapest way to boil water using a kettle, only fill it with the amount of water you plan to use. This will save money and reduce water waste.
On average, an electric kettle has a power rating of 2,500 to 3,000 watts. Although this rating is relatively high, a modern electric kettle only needs a couple of minutes to boil water. This means that boiling a kettle once is likely to use less energy overall compared to other appliances, like an oven or fan heater, which are normally used for longer periods of time.
Use our energy cost calculator to estimate the running costs of your kettle and other appliances. It uses the latest energy price cap and average appliance ratings to show you how much your appliances could be costing you.
Some other ways you can reduce kettle running costs include:
Using an eco-kettle which can use around 20% less energy than a standard electric kettle.
Similarly, using a variable temperature kettle. Variable temperature kettles will only heat the water to a specified temperature. So, if you don’t need water to be fully boiled, they can help to save energy by only heating the water to the temperature you need.
Using a kettle with an automatic shut-off – these kettles will stop heating once the water is fully boiled. Most modern kettles have this feature, but traditional whistle kettles will require manual removal from the source of heat.
If you want to understand your kettle’s running costs at home, the answer starts with how much energy you use each time you boil water. A smart meter in-home display can help you see changes in your household energy use in near real-time, making it easier to understand how small habits, such as boiling only what you need, may affect overall running costs.
What is limescale in your kettle?
Limescale is a chalky mineral deposit left behind when hard water is heated. If you’re wondering whether limescale in a kettle is bad for you, it’s generally considered harmless, although heavy build-up can shorten the life of your kettle or make it less efficient.
Knowing what causes limescale in kettle appliances can help you stay ahead of build-up, especially if you live in a hard water area.
How often should you descale your kettle?
You should descale your kettle whenever you start to see noticeable build-up, though homes in hard water areas may need to do it more often. Regular cleaning is one of the easiest ways to help prevent limescale in a kettle, as it removes deposits before they become harder to manage.
How to descale a kettle
To remove limescale from a kettle, loosen any deposits, add your chosen descaling solution, heat or leave it as directed, then rinse thoroughly before using the kettle again.
We’ve compiled a list of steps to help you learn how to stop limescale in your kettle, which could impact your kettle’s efficiency:
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Choose your products
Choose either white vinegar diluted with water or a kettle descaling product. If using a shop-bought descaler, always follow the manufacturer’s instructions on the packaging.
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Remove loose limescale
Some of the limescale may be easily removed by filling the kettle with water, swirling it around, and then draining it. You may also be able to remove loose limescale by wiping the inside using a damp cloth. If your kettle has a removable filter, rinse it under running water and gently wipe with a soft cloth to remove any limescale deposits.
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Prepare the solution
Fill your kettle with equal parts white vinegar and water. If you plan to use a kettle descaler, prepare the solution according to the manufacturer’s instructions on the packaging for best results.
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Heat or leave the solution as directed
Boiling plain water alone usually won’t clear existing deposits, so if you’re asking does boiling water remove limescale, the answer is usually no. If you’re using vinegar and water, bring the mixture to a boil, then switch off the kettle. If you’re using a shop-bought descaler, follow the manufacturer’s instructions, as some products may need to be left to work without boiling.
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Let it sit
Allow the solution to sit in the kettle for 15-30 minutes, or for the time recommended by the manufacturer if you are using a shop-bought descaler. This gives the solution time to loosen and dissolve the limescale.
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Drain and boil with water
Drain the solution and use a damp cloth to wipe any residue. Then fill your kettle with clean water and boil it once or twice, unless the manufacturer’s instructions say otherwise, to make sure that all traces of descaler are removed. If you notice any lingering odour or taste, repeat the rinse-and-boil step as needed.
While boiling a kettle may seem like a trivial task, kettle running costs can add up over time. By making small changes, such as filling the kettle only with the water you need, you can help keep your home cost- and energy-efficient.
FAQs on maintaining your kettle
Is limescale in a kettle bad for you?
It’s generally harmless to health and more likely to affect kettle performance than the water itself.
What causes limescale in kettle?
Limescale is mainly caused by mineral-rich hard water leaving deposits behind as it heats up.
Is limescale in kettle dangerous?
Limescale in a kettle is usually more of an appliance-maintenance issue than a health risk.
How often should you descale your kettle?
Descale your kettle when you notice visible build-up. If you use it frequently or live in a hard water area, you may need to descale it more often.
How do you remove limescale from a kettle?
To remove limescale from a kettle, fill it with equal parts white vinegar and water, heat the mixture, then leave it to sit for 15–30 minutes before draining and rinsing thoroughly. If using a shop-bought descaler, always follow the manufacturer’s instructions. Boil fresh water once or twice afterwards, unless the instructions say otherwise, to remove any remaining taste or smell. Regular descaling can help your kettle work more efficiently, especially if you live in a hard water area.
If you want to find out how much energy your kettle is using, join millions of Brits and request a smart meter today. With the smart meter in-home display, you can monitor your energy usage in near real-time.
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