I think that copper coil is for their solvent cleaning system John. It sits in a tank of hot water and the solvent is drawn through by a separate pump.
Perhaps , but im right about the steammate , actually it said it on their website when i looked
"Cleaning solution flows through a unique 15 metre copper coil heat-exchanger wrapped around a heated core. This design is dramatically more efficient than a regular hot box system, where cleaning solution flows rapidly through a channelled heated metal block, which then cools down. Our design produces high-heat, even when cleaning at pressures up to 600 psi – see the video."