De-scaling electric kettle

[Andrew Gabriel]

That's a very tiny effect. The element still has to get 3 kW (or whatever it's rated at) out into the water. If there's a layer of insulating scale around it, then the element will be running very much hotter, and fail faster (although nowadays, some other part of the kettle normally fails before the element, with kettles having become "consumables"). Also tends to make the kettle noisier ("kettling";-).

IME, mesh filters get blocked with hard water too, and then when your pour, the water comes out all the wrong places, like round the side of the lid. Mesh filters need descaling more often than the element.

[Set Square]

In some cases, it's a condition of the warranty.

Presumably the element can overheat and self-destruct if the scale provides too much insulation between it and the water.

[Andrew Gabriel]

One method I have used when a) it's someone else's kettle, b) they aren't looking, c) there's no descaller anywhere to be seen, is to switch it on with no water in it for long enough that the residual moisture in the scale on the element has boiled off plus a few more seconds so it's well above boiling (probably some 5 to

10 seconds in total), switch off, and then pour a small amount of cold water in so it splashes on the element. It hisses and spits (beware of the steam), and makes the scale crack and fall off. Of course, if you're unlucky, you'll burn out the element, trip the overtemp, and/or buckle the element, but so far I've always got away with it. It only descales the element itself, not the rest of the kettle of course.

I discovered this at university, where is was quite common for ones colleagues to pop in and switch on your kettle without first checking if there was any water in it, and when it starts making gasping noises and the element is glowing a dull red, then they hold it under the cold water tap. The element doesn't need to be anywhere near that hot for the effect to work though.

[Peter]

Hmm, clever. I just bought a little SDS drill with lots of bits, I'm sure one of them is suitable for attacking limescale.