Sioux's high-efficiency industrial water heaters are among the most efficient on the market today. Sioux water heating systems provide a continuous hot water supply without preheating and no recovery time. The operation is simple. A 100°F temperature rise can be reached in only 3-5 minutes (depending on the unit rating). Outlet temperatures and flow rates can be held at precise levels. Commercial and industrial hot water heating systems are pre-plumbed and pre-wired for easy installation. Diesel, LP, or natural gas; or a combination burner that will burn any of the above fuels.