Dual Boiler 2 Heater
So called "Dual Boiler" machines comprise 2 upright, vertical cylinder boilers, each with a separate heater. Compared to the horizontal steam boiler of Dual boiler one heater machines, the steam quality of this machines is not as powerful, sometimes weak (water surface doubled if cylinder is horizontal mounted). Advantage: Coffee boiler temperature can be adjusted from outside with a control unit (pid). Disadvantage: The coffee quality is not as good as with dual boiler one heater machines with one heater: (1) Size of the coffee boilers is between 0.9 liter to 1.5 liter, the dual boiler one heater machines have a 0.3 liter coffee boiler. (2) There is no fresh cold oxynge rich water injection, just the old boiled through water from months ago (ratio boiler size to espresso shot!)