CGA-8 - 172,000 BTU Output Boiler, Spark Ignition w/o Draft Hood - Series 3 (Natural Gas)

Weil-McLain CGA-8 – Atmospheric Gas-Fired Water Boiler (Model 381359082)

The Weil-McLain CGA-8 is a cast iron, natural draft, gas-fired water boiler suitable for residential and light commercial hydronic heating systems. With a DOE heating capacity of 198,000 BTU/hr and 84% AFUE, the CGA-8 is designed for large heating loads and reliable seasonal performance. The unit supports single- or multi-zone configurations and is equipped for natural gas operation.

System Overview

• AFUE: 84%
• Input Capacity: 233,000 BTU/hr
• DOE Heating Capacity: 198,000 BTU/hr
• Net I=B=R Rating: 172,000 BTU/hr
• Boiler Type: Atmospheric vent, cast iron, gas-fired
• Combustion: Intermittent electronic ignition

Component and Construction Features

• Heat Exchanger: Cast iron sections with factory-assembled push nipples
• Burners: Stainless steel burners for long service life and quiet ignition
• Vent System: Natural draft, 7-inch flue outlet
• Integrated Safety: Factory-installed low water cut-off and blocked vent safety switch
• Controls: Standard electronic ignition module with diagnostics, factory-wired circulator and service switch

Connections and Dimensions

• Water Supply/Return: 1-1/2" NPT
• Gas Inlet: 3/4" NPT
• Relief Valve: 30 PSI ASME-rated (factory-installed)
• Max Working Pressure: 50 PSI
• Shipping Weight: Approx. 616 lbs
• Overall Dimensions: 31-3/4" H × 23" W × 27-1/2" D

Installation Notes

The CGA-8 is supplied as a pre-assembled unit and includes all factory wiring, circulator pump, and safety controls. Venting requires connection to a lined masonry chimney or approved Type B vent. Proper combustion air and draft requirements must be verified during commissioning. Piping layout should conform to primary-secondary or zone-based system design, using either zone valves or individual circulator pumps as specified in the installation manual.

Installation must be completed by a qualified professional in accordance with all applicable local, state, and national codes. Startup requires full combustion analysis and adjustment of gas pressure at the manifold per Weil-McLain factory specifications.

Application Summary

The CGA-8 is a practical solution for larger residential homes, multi-family buildings, and light commercial properties requiring a non-condensing, high-capacity heating appliance. Its cast iron construction, stainless burners, and integrated controls provide a long service life and simplified serviceability.

Compliance & Certification

• CSA certified to ANSI Z21.13 / CSA 4.9
• ASME Section IV-stamped heat exchanger
• Meets DOE efficiency standards for residential boilers