The Navien NFB-399C is an indoor condensing boiler for hydronic space heating. It is a heating boiler, not a combi-boiler with integrated domestic hot water.
Product details
- Maximum input: 399,000 BTU/h.
- Thermal efficiency: 97.5%; this is not an AFUE rating.
- Stainless steel fire tube heat exchanger.
- Indoor wall-hung installation.
- Professional system sizing, gas setup, venting and water treatment are required.
Before ordering
Gas appliances must be installed by a licensed professional in accordance with the manufacturer’s instructions and applicable local codes. Before ordering, confirm the correct fuel type, natural gas or propane, and ensure your site meets the venting, gas-supply sizing, and installation requirements.
Manufacturer product information
Luverlo Warranty
Luverlo warranty notice: Luverlo provides buyers with a full two-year warranty from delivery on products purchased through our online store. Luverlo pays for parts, labor and shipping for covered defects. Read the full warranty terms and claim procedures.
