Evergreen High Efficiency Condensing Gas Boiler (NG or LP)

Weil-McLain Evergreen® Condensing Boiler – Model 383900006

The Weil-McLain Evergreen® 220 (383900006) is a high-efficiency, modulating condensing gas boiler engineered for large residential and light commercial applications. Designed for performance, scalability, and serviceability, this floor-standing unit delivers reliable hydronic heating with a thermal input capacity of 220,000 BTU/hr and an AFUE rating of 95%.

The unit supports natural gas or propane operation (field convertible) and features a stainless steel fire tube heat exchanger for enhanced thermal transfer, corrosion resistance, and long operational life. The Evergreen is equipped with an advanced control platform that accommodates a wide range of system configurations, including multiple-zone and multi-boiler cascade applications.

Core Capabilities

• 95% AFUE Efficiency: ENERGY STAR® certified; reduces fuel consumption compared to standard efficiency units.
• Stainless Steel Heat Exchanger: Fire tube design provides efficient heat transfer and minimizes maintenance requirements.
• Advanced Control System: Integrated ZoneStacking® Technology manages up to 24 programmable heating zones from a single control interface.
• Modulation: 10:1 turndown ratio enables the boiler to adjust firing rate to match demand, ensuring consistent output and improved system efficiency.
• Built-In Cascade Logic: Supports up to eight boilers in a lead-lag configuration for systems requiring up to 1.76 million BTU/hr combined capacity.

Technical Specifications

• Model: Evergreen® 220 (383900006)
• Input Capacity: 220,000 BTU/hr
• DOE Heating Capacity: 203,000 BTU/hr
• Net I=B=R: 177,000 BTU/hr
• Efficiency: 95% AFUE (condensing)
• Heat Exchanger: Stainless steel, fire tube design
• Fuel Type: Natural Gas or LP (field convertible)
• Vent Type: Direct vent, PVC/CPVC/Polypropylene compatible
• Maximum Vent Length: Up to 100 ft (varies by diameter and material)
• Installation: Floor-standing configuration

Installation Notes

This boiler is intended for installation by licensed HVAC or plumbing professionals. The unit includes a built-in circulator and control logic for DHW priority, multiple heating zones, and auxiliary components. Proper venting, condensate drainage, and combustion air supply are critical for code compliance and performance. Manufacturer documentation includes wiring diagrams, flue layout specifications, and commissioning procedures for all system configurations.

System designers can implement the Evergreen® in parallel boiler configurations, using the onboard control platform without requiring external sequencing modules. The user interface provides real-time system status, modulation levels, and fault diagnostics for easier startup and troubleshooting.

Design Features

• ZoneStacking® Support: Control up to 24 heating zones with no external controller required.
• Quiet Operation: Fully insulated chassis and variable-speed fan reduce operating sound levels for noise-sensitive environments.
• Low NOx Emissions: Meets SCAQMD and other regional emissions standards (<20 ppm NOx).
• System Pump Control: Integral relay support for boiler and system pumps, DHW pumps, and auxiliary devices.
• Warranty: 10-year limited on heat exchanger, 2-year on parts (residential applications; commercial terms vary).

Application Summary

The Weil-McLain Evergreen® 220 is well-suited for multi-zone residential hydronic systems, large homes, and light commercial buildings requiring scalable capacity and high efficiency. Designed for flexibility and long service life, the Evergreen® series offers robust performance in modern radiant, baseboard, or fan coil installations with direct vent capabilities and full outdoor reset control.