GV90+ Series High Efficiency Natural Gas Boiler, 105,000 BTU

Weil-McLain GV90+4 – High-Efficiency 105 MBH Natural Gas/LP Cast Iron Boiler

The GV90+4 combines a cast iron primary heat exchanger with a stainless steel condensing secondary, delivering a DOE heat output of 97 MBH and a Net I=B=R of 84 MBH. Rated at 91.2% AFUE, this unit exceeds ENERGY STAR® efficiency targets and is designed for hydronic systems requiring compact installations and sealed combustion performance.

Core Features & Specifications Efficiency & Capacity • 91.2% AFUE • 105 MBH input • 97 MBH DOE output • 84 MBH I=B=R net weil-mclain.com +15 weil-mclain.com +15 acwholesalers.com +15 Dual Heat Exchanger Design • Cast iron primary • Stainless steel secondary condensing side • 7-pass primary + 2-pass secondary flue flow ecomfort.com +4 weil-mclain.com +4 sidharvey.com +4 Venting/Fuel Configurations • 3″ PVC/CPVC/PP vent compatible • Direct vent, direct exhaust, or concentric options • Field-convertible between natural gas and LP acwholesalers.com +13 weil-mclain.com +13 afsupply.com +13 Circulator Strategy • Built-in dual circulator system supports low return temperatures (≥ 60 °F), eliminating the need for external mixing devices externalassets.unilogcorp.com +3 weil-mclain.com +3 supplyhouse.com +3 Control & Diagnostics • Integrated boiler control module with snap-in diagnostics, outdoor reset capability, and 100 k-cycle rated terminals weil-mclain.com +9 weil-mclain.com +9 externalassets.unilogcorp.com +9 Benefits for Contractors Easy Install & Service – Factory-assembled and wired out-of-the-box; sealed combustion simplifies venting; hinged panels provide full access for service. Robust & Retrofit-Ready – Cast iron and stainless steel construction ensures long service life. Seven-pass design handles debris flow, making it ideal for older hydronic systems weil-mclain.com +1 ecomfort.com +1 . Code-Compliant & Durable – ASME Section IV rating, CSA listed, ENERGY STAR certified, and hydrostatically tested; supports both residential and light commercial installations . Installation & Specification Summary Parameter Value Fuel Type Natural Gas (LP conversion kit included) Venting 3″ PVC/CPVC/PP, direct vent configurations Ignition Hot surface ignition; sealed combustion design Dimensions ~30.75″ × 24.6″ × 30.75″ (W × D × H) thegranitegroup.com +3 afsupply.com +3 sidharvey.com +3 Typical Application Baseboard, radiator, or radiant panels Clearances Combustible floor permitted; see manual Weight ~353 lbs Warranty 20-year primary / 5-year secondary / 2-year parts (residential) Summary The Weil-McLain GV90+4 is a high-performance, contractor-friendly gas boiler offering the durability of cast iron, the efficiency of condensing stainless heat exchangers, and a sealed combustion design for safer, flexible installations. Its dual-circulator setup allows direct connection to modern low-temperature systems, while simplified diagnostics and a compact footprint enhance field installation and serviceability.

Weil-McLain GV90+ Series, Model GV90+4 – High-Efficiency Natural Gas Boiler with Dual Heat Exchanger

The Weil-McLain GV90+4 is a direct vent, high-efficiency, cast iron gas boiler with an integrated stainless steel secondary heat exchanger. Designed to meet the demands of modern hydronic heating systems, the GV90+ delivers 91.2% AFUE, offering a reliable and fuel-efficient option for residential hot water heating applications. This model supports both natural gas and LP configurations with the included conversion kit.

Performance Highlights

• AFUE Efficiency: Rated at 91.2%, suitable for ENERGY STAR® criteria in most regions.
• Heating Capacity (DOE): 97,000 BTU/hr
• Net I=B=R Output: 84,000 BTU/hr
• Input Rate: 105,000 BTU/hr
• Combustion: Sealed combustion with spark ignition and automatic vent damper

Heat Exchanger Construction

• Primary: Cast iron with factory-assembled, wet-base sections
• Secondary: Condensing stainless steel heat exchanger designed to recover latent heat from flue gases
• Target Wall: Ceramic fiber for high-temperature durability and combustion zone protection

Vent and Fuel Configurations

• Venting Options: Supports direct vent, direct exhaust, and concentric systems using 3-inch PVC, CPVC, or polypropylene
• Fuel: Natural gas standard; LP conversion kit included
• Burner: High-performance power burner matched to firing rate and heat exchanger

Design and Installation Considerations

• Dimensions: Length: 30-3/4" – suitable for applications with limited footprint
• Flue Configuration: 3" vent pipe termination with a maximum vent length depending on elbows and configuration
• Circulator Strategy: Integrated dual circulator configuration supports outdoor reset control and system zoning
• Control Package: Integrated boiler control with user interface; accepts external temperature reset sensors and priority DHW control

Job Site Advantages for Contractors

• Ships fully assembled and pre-wired for reduced installation labor
• Multiple venting configurations reduce installation restrictions on retrofit and new construction jobs
• Easy service access to key components via removable front and top panels
• ASME-rated cast iron heat exchanger with 20-year limited warranty

Technical Summary

• Model: GV90+4
• Boiler Type: Gas, Hot Water
• Ignition: Intermittent electronic ignition with flame sensing
• Max Working Pressure: 50 PSIG
• Approval: CSA Certified; ASME Section IV compliant

Summary

The Weil-McLain GV90+4 is engineered for high-efficiency gas-fired hot water heating applications where cast iron durability is required alongside the energy savings of condensing technology. With flexible venting, dual heat exchangers, and integrated controls, this unit is ideal for residential system upgrades and high-efficiency retrofits.