I finally got round to cleaning my coffee machine. The machine, a Fracino Bambino 2E makes splendid espresso but the steam wand and hot water outlet have an unpleasant rancid taste. As an almost exclusive drinker of espresso it has taken me a while to face up to this problem. #truelove likes a hot chocolate though, so it was time to bit the bullet.
First step, I took out the hot water outlet tube. This tube sits in the boiler water feeding heated water from inside the boiler to the hot water outlet. It was filthy! As an experiment I tried a few different cleaning solutions. It the end, it turned out that standing the pipe in a citric acid solution for a few hours cleaned it off without the need for scrubbing. The inside of the pipe cleaned up nicely with the aid of a couple of pipe cleaners.
Next, the boiler itself. This is a big beast holding more than twelve litres of water. (Over two gallons) The picture on the left is the best view I could get of the inside of the boiler. Black, with added black. I filled the boiled with citric acid solution and left it overnight. After syphon out the liquid I could actually see metal inside the boiler! (Blurry picture on the right)
To ensure that I had all the dirt and citric acid out from the boiler I repeatedly filled the boiler to the top, heated it to just sort of boiling then syphoned it out. I did this perhaps ten or twelve times. Long, slow, process.
I visited to Forth Engineering where the guys there very generously let me have these copper washers as well as the high temperature rubber insert washers which were actually a better fit the original copper washers.