CGA-5 - 98,000 BTU Output Boiler, Spark Ignition - Series 3 (Natural Gas)

Weil-McLain CGA-5 – 98,000 BTU Gas-Fired Cast Iron Boiler, Atmospheric Vent

The Weil-McLain CGA-5 is a gas-fired cast iron boiler designed for residential hydronic heating systems. With an input of 112,000 BTU/h and a DOE heating capacity of 98,000 BTU/h, it delivers consistent and efficient performance across a wide range of installation environments. The unit operates with a natural draft venting system and includes integral safety and control features for dependable long-term operation.

Core Performance Specifications

• Input Capacity: 112,000 BTU/h
• DOE Heating Capacity: 98,000 BTU/h
• Net I=B=R Rating: 85,000 BTU/h
• AFUE: 84%
• Fuel Type: Natural Gas
• Ignition System: Intermittent electronic ignition

Key Engineering Features

• Cast Iron Heat Exchanger: ASME-certified for long service life and thermal efficiency
• Built-in Low Water Cutoff: Factory-installed to protect the heat exchanger from dry firing
• Stainless Steel Burners: Designed for quiet ignition, stable combustion, and corrosion resistance
• Vertical Flueways: Simplifies brush cleaning and maintains optimal draft characteristics
• Top Cleaning Access: Allows for quick maintenance without disassembling the flue collector

Installation & Application

• Boiler Type: Natural draft, non-condensing
• Vent Connection: 6-inch diameter
• Combustion Air: Uses indoor air; not suitable for sealed combustion applications
• Dimensions: Approx. 19-1/2" W × 28-1/2" D × 31" H
• Weight: ~385 lbs
• Electrical Requirements: 120V, 60Hz, 15A circuit

The CGA-5 is designed for closed-loop, forced hot water systems operating at a maximum working pressure of 50 psi. It is compatible with traditional fin-tube baseboard, cast iron radiators, and radiant panel heating configurations. Proper sizing and installation in accordance with local codes and manufacturer guidelines are essential for safe and efficient operation.

Recommended Installation Practices

Professional installation is required. This includes combustion analysis, gas pressure verification, venting evaluation, and compliance with all applicable plumbing and mechanical codes. Weil-McLain provides detailed piping and wiring schematics to support contractor fieldwork.

Control & Safety Features

• Integrated Control Module: Manages ignition sequence, circulator activation, and diagnostic monitoring
• Flame Rollout Safety: Rollout switch included for overfire protection
• Blocked Vent Switch: Monitors draft and prevents unsafe operation

The CGA-5 is a field-proven solution for contractors requiring a durable, gas-fired atmospheric boiler with high thermal output and simplified serviceability. Its robust cast iron construction and built-in safety controls support long-term system performance in residential hydronic heating applications.