The Legend 2000® series delivers an exceptional 90% thermal efficiency by combining advanced pre-mix burner design and an extruded, self-baffling copper heat exchanger for outstanding efficiency and unsurpassed performance. The heat-exchanger design exposes more surface area to the combustion system to maximize heat transfer. Each model features a small footprint with zero side clearance for outstanding adaptability perfect for retrofits. The exclusive Dia-Scan® solid-state self-diagnostic system helps make operation and troubleshooting quick and easy.