The Navien Common Vent System provides an easy way to install the vent system for up to 8 Navien NPE water heater or NHB boiler units. By sharing the main intake and exhaust vent pipes, effective system venting is available with less venting materials and minimal number of penetrations on the walls or roofing.

A Navien combi boiler can cost anywhere between $3,500 to $6,000. Where your final cost for the unit hits is solely based on what model is suitable for your home. A few factors that can impact the cost of the combi boiler are the number of fixtures in your home, the space heating demand, and hot water demand.