Descaling a kettle and removing limescale: vinegar, citric acid, and the $10 to $18 products at Bunnings that do it faster

The white crust in the kettle is limescale: calcium carbonate that drops out of hard water every time it boils, and that any food-safe acid will dissolve again. You don’t need to buy anything to get rid of it: white vinegar or a spoon of citric acid does the job, and this page gives both methods. If you’d rather buy a product, the Hillmark Expresso Kleen sachets at Bunnings ($10.49 for three on 1 November 2026) are citric acid pre-measured for kettles and coffee machines, and Durgol is the descaler the espresso-machine makers name. For taps, showerheads and glass, CLR ($17.49) and Glitz ($12.99) are the surface removers. We can’t show Amazon prices; the Amazon buttons show today’s.

How to descale a kettle, two ways

Vinegar: pour in equal parts white vinegar and water, enough to cover the element or the scale line, bring it to the boil, switch off and leave it an hour, overnight for a thick crust. Tip it out, brush any loose flakes off with a soft brush, then boil and discard two kettles of clean water so the tea doesn’t taste of pickles. Use white vinegar; brown stains.

Citric acid: fill the kettle, add one to two tablespoons of food-grade citric acid from the baking or cleaning aisle, boil, leave it 20 minutes, empty, rinse, and boil one kettle of clean water. It works faster than vinegar, doesn’t smell, and it’s the same chemistry Hillmark sells in a sachet, which is why the Expresso Kleen is our pick for anyone who’d rather not measure.

Either method is fine for stainless and glass kettles. For aluminium, copper or brass, keep it dilute and short: Hillmark’s own Scalex label warns against prolonged contact with those metals, and the same goes for most acid descalers.

Which descaler should you buy?

Buy by what you’re descaling, because the products split into two groups that shouldn’t be swapped. Inside things you drink from, the kettle, the coffee machine, the urn, you want a product sold for that: the Hillmark Expresso Kleen (citric acid, three sachets, $10.49, sold for kettles, jugs, urns and coffee machines), the Sunbeam KE0100 (250 mL liquid “for all coffee makers and kettles”), Breville’s Kettle Cleaner (Breville’s own, with a 12-month replacement warranty on the listing and almost no other detail), Durgol 298 Universal Express (750 mL, Swiss, sold for all coffee and espresso machines, “food safe, leaves no chemical residue after rinsing”, with a claim to work five to ten times faster), and Knaus (300 g powder with four measured doses marked on the bottle, for kettles, irons, dishwashers and steamers).

On surfaces, the showerhead, the tap aerator, the glass screen, the kettle’s outside, you want a surface remover, and these aren’t sold for food contact: CLR (1 L concentrate that makes 2 L, plant-derived lactic acid by its listing, and no kettle or coffee machine claim on the page) and Glitz (a 750 mL ready-to-use trigger spray whose listing names showerheads and “tea and coffee pots”). For the dishwasher and washing machine, Hillmark Scalex ($13.99) is the powder sold for their internal pipes and valves, with the metal warnings above.

Where the scale comes from, and how to slow it

Scale is the dissolved calcium and magnesium in hard water coming out of solution when it’s heated. How fast your kettle crusts up is a map of Australia: Adelaide and Perth kettles need descaling monthly, Brisbane’s every few months, Sydney and Melbourne’s maybe once a year, and tank and bore water vary from nothing to worse than Adelaide. Our city tap water pages give the hardness figures.

Descaling removes it; only softening prevents it. The honest options, in order of cost: a jug cartridge sold for limescale, such as the Brita Maxtra Pro Limescale Expert in our Brita cartridge guide or the Philips Softening+ cartridges at Bunnings, which slow the crust in a kettle you fill from the jug; reverse osmosis at the kitchen tap, which removes the hardness from drinking water; and an ion-exchange softener for the whole house, which is the only fix for the hot water service and the shower screen. The water softener guide covers why the “salt-free descaler” gadgets on Amazon and in Bunnings’ marketplace aren’t on this page.

Coffee machines: use the maker’s product

Espresso machines scale on the boiler and the solenoid where you can’t see it, and the sensor that tells you to descale is counting litres, not looking. Use the descaler the maker sells (Breville, De’Longhi and Sunbeam all do) or a product sold for espresso machines such as Durgol, follow the machine’s descale cycle, and don’t put vinegar through a machine with a warranty, because some makers exclude damage from it. On hard water, a filter in the tank slows the whole thing down; the coffee machine water filter guide matches the cartridge to the machine.

The one trap

Using a surface limescale remover inside the kettle because it’s already under the sink. CLR and Glitz are sold for baths, taps and tiles, and neither listing makes a claim for the inside of anything you drink from; the Hillmark and Sunbeam products cost less anyway. Keep the surface products for the showerhead, the aerator and the glass, where they’re the right tool, and keep the acid that goes in the kettle to vinegar, citric acid or a product sold for kettles.

What we left out and why

• De’Longhi EcoDecalk and Breville Eco liquid descalers (Amazon Australia). Maker-specific coffee machine products, covered by the “use the maker’s product” rule.
• White Magic and Chef Aid descaling tablets and stainless “kettle descaler” balls (Amazon Australia). Tablets are measured citric acid at a premium; the stainless balls collect scale rather than remove it and need a listing with evidence before we’d include them.
• Marketplace coffee descaler liquids at Bunnings ($18.90 to $37.95). Unbranded or re-labelled; the Sunbeam and Durgol are the same thing with a maker behind them.
• Vevor “salt-free descaler” and electronic water conditioners. We found no test evidence for them; the softener guide explains.
• Enviro Wizard, Diversey and other 20 L commercial descalers (Bunnings marketplace). Trade sizes.