My wife was trying to clean our kettle
I said, it needs CLR
she asked what CLR is
I said Calcium Lime and Rust. There is also Lime-Away.
She put the CLR in there. Then she washed it out many times. All of the mineral deposits washed away. She rinsed it out with water many more times, and then eventually cleaned it with vinegar after rinsing it many times. At least, I think that’s how she cleaned it. She’s the kettle cleaner, I don’t know much about it, other than that CLR exists.
It was very clean for a few months.
We got a regular kettle after that
Like others have said, all it takes is a weak acid. I use white vinegar because it’s cheap and I already have it on hand, but lemon/lime juice or whatever will do in a pinch too.
I have really hard water at my work and all I ever need to clean my kettle is white vinegar and time. If it’s not to bad, I use a splash of vinegar (a tablespoon or several) and enough water to cover the buildup and be swirlable. Then just let it sit and work for 20 minute to an hour. Rinse well and you’re done.
If I’m impatient and want to speed it up (or just want to feel like I’m contributing effort), I’ll warm it up a little, swirl it around it every so often, or give it a light brushing from time to time to dislodge any loose crusties.
If the buildup is bad, you don’t really need to dilute the vinegar. If there’s still residue after an hour or two, you can dump it if you like. and rinse out any loosened buildup, and refresh the vinegar. Repeat as needed.