Natural GAS Boiler, 233 MBH, 87% AFUE, Series 3

Williamson GWA-233 Series 3 – Gas-Fired Atmospheric Cast Iron Boiler with Integrated Venting Control

The Williamson GWA-233-N-T-S3-W is a natural gas-fired, non-condensing hot water boiler built for residential and light commercial applications. With an input rating of 233,000 BTU/hr and an 84.0% AFUE, this unit delivers reliable hydronic performance across multi-zone systems and larger heating loads.

This model is part of the GWA Series 3 product line, constructed with a cast iron heat exchanger and equipped with stainless steel burners, an automatic vent damper, flue baffles, and an intermittent electronic ignition system. The design supports conventional chimney venting and is compatible with closed-loop heating applications.

Core Specifications

• Input: 233,000 BTU/hr
• DOE Heating Capacity: 194,000 BTU/hr
• Net I=B=R Rating: 169,000 BTU/hr (water)
• AFUE: 84.0%
• Fuel: Natural Gas

Design & Component Features

• Heat Exchanger: Cast iron block construction with integrated flue baffles for enhanced heat transfer
• Burners: Atmospheric stainless steel burners with intermittent electronic pilot ignition
• Vent Damper: Factory-installed automatic damper to reduce off-cycle standby losses
• Cabinet: Heavy-gauge steel jacket, factory insulated to minimize jacket loss
• Controls: Includes service switch, wiring junction box, and standard aquastat

Installation Requirements

The GWA-233-N-T-S3-W is designed for use in closed-loop hydronic systems with standard circulator and expansion tank configurations. It vents through a masonry chimney or Type B vent, per Category I guidelines. Installation must follow all applicable mechanical and gas code regulations. Ensure proper combustion air availability and clearance for maintenance access.

Typical Applications

• Mid-to-large residential heating with high BTU load requirements
• Baseboard and panel radiator systems with multi-zone piping
• Projects requiring standard venting through lined chimney flue

Notable Performance Enhancements

• Stainless Steel Burners: Reliable combustion with corrosion resistance
• Flue Baffle System: Increases thermal efficiency and improves heat distribution
• Intermittent Pilot System: Reduces standby gas usage and ensures consistent ignition
• Automatic Vent Damper: Decreases heat loss and improves seasonal efficiency

Warranty Coverage

• Heat Exchanger: 20-year limited warranty
• Parts: 1-year limited warranty