Rinnai RCB399AN Commercial Condensing Solo Boiler, 399,000 BTU, Natural Gas

The Rinnai RCB399AN is the 399,000 BTU model in the RCB Series of indoor, wall-mounted commercial condensing boilers. Running on natural gas at 97% efficiency, it serves heat-only applications in commercial buildings where floor space is limited.

A stainless steel heat exchanger with an ASME H stamp and ultra low NOx combustion form the core, and a 10:1 turndown ratio lets output follow the load. A 7 in. LCD touch screen handles setup, and the boiler works with Wi-Fi and building management systems.

It vents as twin pipe and uses direct electronic ignition. Up to 8 units can operate in cascade and up to 4 can share a common vent for larger systems. Connections are a 1 in. MNPT gas line, 1-1/4 in. MNPT water connections and a 1 in. MNPT condensate drain.

Highlights

• 399,000 BTU (117 kW) maximum input on natural gas

• 97% efficiency with a 10:1 turndown ratio

• Stainless steel heat exchanger with ASME H stamp; ultra low NOx

• 7 in. LCD touch screen; Wi-Fi and BMS compatible

• Cascade as many as 8 units; up to 4 can share one vent

Specifications

Good to know

• Gas-fired appliance: it must be installed, vented and commissioned by a qualified installer in line with local codes and the manufacturer's installation manual.