Factor to consider selection of boiler?
Since in UK = England, a hot water heater is called a boiler and perhaps even a tea kettle, you need to clarify. Do you need huge quantities of steam at 2000 PSI or just a small boiler? So some factors are temperature, pressure, kilograms per second, explosion contingencies, Corrosion due to parts per billion of water impurities, and purpose of the the boiler. Neil