Rugged, Weather-Resistant Design Hotsy has introduced a new chassis design for the 900 Series of hot water pressure washers. This new design is heavier than the previous model, and is made of rugged steel painted with an epoxy powder-coat finish for all-weather resistance. All 900 Series models are powered by electricity with 1,725-rpm motors, and produce cleaning power of 2,000 psi and 3.9 gpm.