I love this! Truth is, I like a challenge. And I’ve been set many challenges by limescale for over 35 years now. I like it best when someone says I won’t be able to do it! I can break limescale down (sometimes in just a few minutes) by using a acid/water solution - sent through your pipes by a clever little machine. Most of my work is descaling combi boilers. As combi boilers use mains water then they are prone to limescale formation. There are also thermal store hot water heaters. And often there are just pipes that need descaling.