I used to be a boiler surveyor for my sins, having spent the thick end of 15 years as an engineer at sea and almost the rest of my working life in brewing, and food and drink with boilers.
I used to do small boilers in coffee machines in the likes of Starbucks to the boilers at Ferry Bridge power station. They wanted me to do the heritage work on steam rail and traction engines as well. I took a long look at it and decided that I really didn't want to be involved, there are far too many enthusiastic amateurs around, who do their best, but it's really not enough. I could see that I’d inspect something and then be waking up in the middle of the night wondering what I’d missed.
As someone who likes to make sure a job is done not only correctly, but to a high standard of correctly, it was one of the reasons I left doing inspections.
Let the people who know exactly how to build boilers, build them and then use a company like British Engineering Services do the inspections. Keep them right and you won’t have a problem don’t and you will. The link below is to an article in the Daily Mail about a coffee boiler explosion.
Sainsbury Coffee Boiler