Guide · Kettles
How to descale a kettle: the cheap, safe ways to shift limescale
Four ways to descale a kettle, from kettle makers and UK water companies: citric acid, white vinegar, lemon and branded descalers, plus how to keep scale away.
Working out how to descale a kettle is mostly about picking a method your kettle’s maker is happy with. Citric acid, white vinegar, lemon and branded descalers all shift limescale, and kettle makers such as Tefal and Russell Hobbs publish steps for most of them. We haven’t tested this in person. This guide pulls together kettle makers’ own instructions, advice from UK water companies and the Drinking Water Inspectorate, and descaler prices checked at UK retailers on 3 Oct 2026. Read how we compare.
Why kettles fur up
Limescale comes from the water, not the kettle. The Drinking Water Inspectorate (DWI) explains that hardness is caused by dissolved calcium and magnesium, and that hard water leaves scale on kettles, irons and other appliances. Cambridge Water says more than 60% of UK homes have hard water.
The DWI groups water by its calcium carbonate content:
| Hardness | mg/l as calcium carbonate |
|---|---|
| Soft | up to 100 |
| Slightly hard | 100–150 |
| Moderately hard | 150–200 |
| Hard | 200–300 |
| Very hard | more than 300 |
Your water company can tell you where your postcode sits. The DWI notes that its own map can’t show every local variation.
Scale shows up differently depending on the kettle. Cambridge Water explains that in metal kettles it sticks to the sides, while in plastic kettles, which have smoother walls, it tends to float as a film on the water.
How often to descale
Both Russell Hobbs and Tefal suggest descaling at least once a month. Tefal adds that you’ll need to do it more often in a very hard water area. In a soft water area you may get away with much less. A good rule is to descale when you can see a chalky layer on the element or base, or flakes in your drinks.
There’s a practical reason not to leave it too long. Tefal says a scaled element passes less heat to the water, and that scale build-up is a common reason a kettle switches itself off before it boils. Russell Hobbs notes in one of its manuals that scale stops the noise suppressor working, so the kettle gets louder. The same manual says faults caused by scale may mean a repair charge under guarantee.
Who it isn’t for: this schedule is for people in hard water areas. If your water is soft, descale when you see scale rather than by the calendar.
How to descale a kettle: four methods
Before you start, check your kettle’s manual. Makers don’t all agree, and Tefal warns against using any method other than the ones it recommends. Russell Hobbs says any descaler you use must be suitable for plastic products.
1. Citric acid
Citric acid is odourless, which makes it the least antisocial option. Tefal’s method is:
- Boil half a litre of water.
- Add 25g of citric acid.
- Leave it for 15 minutes.
- Empty the kettle and rinse it five or six times.
- Repeat if any scale is left.
Who it isn’t for: anyone whose kettle maker specifies a different product. Check first.
2. White vinegar
Vinegar works, but it smells strong, as Russell Hobbs points out. Instructions vary more here than with any other method:
- Tefal: pour half a litre of white vinegar into the kettle and leave it for an hour without heating it. Then empty and rinse five or six times.
- Cambridge Water: half-fill the kettle with water, add two tablespoons of white vinegar, leave it for four hours, then empty it, remove the loosened scale and rinse.
- Russell Hobbs: use white wine vinegar mixed with cold water and leave it overnight. Then empty, refill with fresh water, boil and pour away.
None of these three methods boils the vinegar itself. Russell Hobbs’ final step is to boil a kettle of fresh water and pour it away, which also helps clear the smell.
Who it isn’t for: anyone who can’t stand the smell. Citric acid does the same job without it.
3. Lemon
Russell Hobbs lists lemon and water, boiled in the kettle, as another option. It doesn’t give exact quantities, so treat it as a light-touch method and rinse well afterwards. If scale is still there, move on to citric acid or a descaler.
Who it isn’t for: anyone who wants a measured, repeatable method. Tefal’s citric acid steps give exact amounts; lemon doesn’t.
4. A branded descaler
Branded descalers are quick and come with their own instructions, which is the main thing to follow. Two we found at UK retailers:
- Russell Hobbs Multi Purpose Descaler (21220). £3.99 at Russell Hobbs UK, checked 3 Oct 2026. Russell Hobbs’ kettle instructions are to mix 50ml with a litre of water, heat until it fizzes, leave it for several minutes, then empty and rinse twice. Russell Hobbs says it’s suitable for kettles and coffee machines. See it at Russell Hobbs UK.
- Quickshine kettle descaler sachets, pack of three. £4.99 at Lakeland, checked 3 Oct 2026. Lakeland’s instructions are to boil the kettle, drop in a sachet, leave it to fizz for about 25 minutes, then rinse. See them at Lakeland.
Who it isn’t for: anyone happy with a cupboard staple. Citric acid or vinegar does the job for less per use.
What not to do
- Don’t scrub the element. Tefal says never to rub the heating element with a cloth or anything abrasive. Descaling is enough.
- Don’t use harsh cleaners on the outside. Tefal warns that abrasive products and detergents can discolour plastic. A damp cloth, with a drop of vinegar if needed, is what it suggests.
- Never put the kettle or its base in water.
- Don’t skip the rinse. Both Tefal and Russell Hobbs build several rinses into their steps.
Don’t forget the filter
Most kettles have a mesh filter in the spout that catches loose flakes. Tefal suggests cleaning it regularly, either by brushing it or soaking it in diluted vinegar or citric acid. If your filter lifts out, soak it separately while you descale the kettle.
How to keep limescale away
You can’t stop hard water, but you can slow the build-up:
- Boil only what you need. Cambridge Water recommends this, and SES Water suggests boiling fresh water rather than reboiling what’s left.
- Empty the kettle after use. Tefal recommends it.
- Rinse plastic kettles often. SES Water says regular rinsing helps with the floating film of scale.
- Try a scale collector or a filter jug. SES Water mentions stainless steel wire scale collectors that sit in the kettle. The DWI says some filter jugs with ion-exchange resin may reduce kettle scale, though they only deal with part of the water’s hardness.
If you’re shopping for a new kettle anyway, a model with a removable filter makes upkeep easier.
Where to go next
Our guide to the best kettles covers the wider range, and we’ve picked out the best kettles under £50 and the best quiet kettles. For pour-over, see the best gooseneck kettles. If your water is hard, our guide to the best tea for hard water may help too.
FAQ
What’s the best way to descale a kettle? The one your kettle’s maker recommends. Citric acid is odourless and quick, and Tefal publishes a simple method using 25g in half a litre of boiled water.
Can you descale a kettle with vinegar? Yes, if your manual allows it. Tefal, Russell Hobbs and Cambridge Water all give vinegar methods, though they differ on strength and timing.
How long does it take to descale a kettle? It depends on the method. Tefal’s citric acid method takes about 15 minutes plus rinsing, while vinegar methods range from an hour to overnight.
Why does a kettle switch off before it boils? Tefal says scale build-up is a common cause, so descale it first. If the kettle was switched on empty, Tefal’s advice is to let it cool, refill it and wait for the cut-out to reset.