For those that don't mind paying a bit more there's of course non-DIY solutions that do the same. We went all out and bought a Quooker with our new kitchen: boi

For those that don't mind paying a bit more there's of course non-DIY solutions that do the same. We went all out and bought a Quooker with our new kitchen: boiling water, cold and filtered water, and carbonated water. Of course it helps that here in the Netherlands, the tap water is basically mineral water. It's a luxury, but we really love it.