- 97.5% TE Industry Leading Thermal Efficiency
- Patented stainless steel fire tube heat exchanger
- 160 PSI maximum operating pressure
- Advanced controls with intuitive 7” color display
- Up to 15:1 TDR (turndown ratio)
- BAS communication capability
- Common vent up to 4 and cascade up to 32 units
- Top & bottom piping
NFB-399C
HIGH EFFICIENCY CONDENSING HEATING BOILER