Clean the kettle with vinegar

I’m an avid tea drinker, so every now and then I notice that my kettle has a build up of scale:

This is my cue to pull out the household white vinegar (ordinary cheap stuff I use for all sorts of things). I pour some into the bottom of the kettle, hopefully above the dirty mark line, and then let it sit.

One hour later, my kettle looked a fair bit cleaner, but not done yet. I emptied out the vinegar and refilled for another go:

And this was after the second hour. Much cleaner! If I hadn’t wanted a cup of tea (two hours, I mean, come on!) I might have waited longer still.

A couple of important tips:

1. Don’t boil the kettle with the vinegar inside! NO, REALLY. You will notice immediately that you have erred, and there will be regret. I unplug my kettle and put a tea towel over the top so that I have two lines of defence against accidentally doing this.
2. Rinse the kettle out thoroughly before boiling it again with water. Otherwise that next cuppa is not going to be quite as good as you would hope!