CGA-25 - 27,000 BTU Output Boiler, Spark Ignition - Series 3 (Natural Gas)

Weil-McLain CGA-25 Gas Boiler – 27,000 BTU, Cast Iron, Natural Draft, Series 2

The Weil-McLain CGA-25 is a gas-fired, cast iron water boiler engineered for dependable performance in residential hydronic heating applications. With a net I=B=R rating of 23,000 BTU/hr and 84% AFUE, this unit is optimized for systems requiring a compact footprint, quiet operation, and consistent output.

Designed as part of the CGa Series 2, the CGA-25 integrates essential safety and operational features into a durable, low-profile design. It includes factory-installed components such as a low water cut-off and intermittent electronic ignition system, streamlining field installation and ensuring compliance with typical code requirements.

Product Highlights

• Cast Iron Heat Exchanger: Sectional design provides uniform heat transfer and long-term corrosion resistance.
• Intermittent Spark Ignition: Eliminates the need for a standing pilot, improving energy efficiency and reliability.
• Natural Draft Venting: Standard 4" B-vent compatible; maintains simplicity and ease of installation in existing systems.
• Built-in Low Water Cut-Off: Factory-mounted control ensures safe operation in low water conditions, minimizing risk of damage.
• Service Access: Hinged front panel and control layout allow for straightforward diagnostics and maintenance access.

Technical Specifications

• Model: CGA-25 Series 2
• Input Capacity: 33,000 BTU/hr
• DOE Heating Capacity: 27,000 BTU/hr
• Net I=B=R Rating: 23,000 BTU/hr
• AFUE: 84%
• Fuel: Natural Gas
• Venting: 4" Natural Draft
• Ignition System: Intermittent Spark Ignition (Electronic)
• Construction: Cast Iron Sections
• Boiler Dimensions: Approx. 12-1/2" W x 27" D x 29-3/4" H

Installation Notes

This unit is designed for standard atmospheric venting and requires a properly sized chimney or vent connector per local code. System piping must accommodate hydronic loop design practices, and expansion tank sizing should be verified based on total system volume. The CGA-25 ships with a Taco 007 circulator, relief valve, and vent damper. While compact, the boiler must be installed with adequate clearance for service and ventilation.

Applications & Considerations

• Ideal For: Small residential zones, point-source heating in multi-unit buildings, or tight mechanical spaces where output requirements are modest.
• Serviceability: Pre-wired controls and accessible piping connections reduce labor time during installation and routine servicing.
• Code Compliance: Meets or exceeds national energy code requirements; suitable for installation in jurisdictions adhering to DOE efficiency mandates.

Summary

The Weil-McLain CGA-25 boiler is an efficient, compact, and low-maintenance solution for small-scale hydronic heating systems. With field-proven components and a design that simplifies both installation and long-term service, it is well-suited for contractors seeking reliable equipment for baseboard or radiator applications.