Slant/Fin’s commercial line of the VGH boilers feature next generation duo stainless steel water tube heat exchangers with larger water passages to increase the heat output for its size, Slant/Fin says. The lower pressure drop on the water side contributes to the compact size and the lower pressure on the flue gas side contributes to the longer approved vent lengths (up to 481’). A stainless steel premix burner reduces excess air and provides efficient and reliable direct spark ignition. Integrated combustion analyzer test ports are standard on all models and the vent connection is deigned to accept PVC, CPVC, polypropylene and stainless steel, the company notes. The onboard control has four built-in cascade program modes, allows for remote operation controlling of the heating, DHW and boiler sequencing and has the ability to cascade up to 16 boilers.