The Gradient syncFurnace combi furnace is a stainless steel, condensing, dual-pass boiler and burner in one unit for in-floor, furnace, and hot water heating. With 150,000 BTUH max burner input, the unit comes with a direct vent, modulating, natural gas or propane burner, with two or three-in. CPVC,
polyproplyne, and stainless steel venting options. Other features include an internal Caleffi auto-air vent, 30 psig pressure relief valve, and condensation trap.