Rinnai RCB301AN Commercial Condensing Boiler, Natural Gas, 301,000 BTU

The Rinnai RCB301AN is an indoor, wall-hung commercial condensing boiler for heat-only applications such as schools, restaurants and light commercial buildings. It modulates from 30,100 to 301,000 BTU/h on natural gas and reaches 97% thermal efficiency.

Its heat exchanger uses corrosion-resistant 316L stainless-steel water tubes, and the AHRI heating capacity is 254,000 BTU/h. Outdoor reset comes standard, the central heating setpoint ranges from 86 to 180 F, and sound output is about 55 dB(A). A 7 in. LCD touchscreen speeds commissioning, with Wi-Fi, a 0-10V BMS input and Modbus for building integration; BACnet and LonWorks need optional adapters.

Venting runs in 4 in. PVC, CPVC, PP or stainless as twin pipe or concentric, or with room air, with exhaust runs of 10-140 ft and intake up to 140 ft equivalent. Up to 8 boilers can cascade and up to 4 can share a common vent. Pump relays for boiler, system and indirect circuits are integrated, though circulators are not included. It is configured for natural gas from the factory, and LP conversion kits exist.

Highlights

• Modulates 30,100-301,000 BTU/h with a 10:1 turndown ratio

• 97% thermal efficiency; AHRI heating capacity 254,000 BTU/h

• 316L stainless-steel water-tube heat exchanger, Low-NOx

• 7 in. LCD touchscreen, Wi-Fi, 0-10V BMS input and Modbus

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

• 1 in. NPT gas, 1-1/4 in. NPT supply/return, 1 in. NPT condensate

Specifications

In the box

• Wall-mount bracket and screws

• 75 psi pressure-relief valve

• Outdoor temperature sensor

• Manuals

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.