Combi Wall Mount Natural Gas Boiler, 120,000 BTU

Weil‑McLain AquaBalance™ AB‑120‑C – 120 MBH Condensing Combi Boiler

The AquaBalance™ AB‑120‑C is a wall‑mounted, high‑efficiency combi boiler that delivers space heating and domestic hot water in a single compact unit. Rated at 95% AFUE, with a 10:1 modulation turndown, stainless steel boiler-side heat exchanger, and a flat‑plate DHW exchanger capable of ~4 GPM at a 70°F rise, it meets ENERGY STAR and Low‑NOₓ requirements :contentReference[oaicite:1]{index=1}.

✅ Key Technical Highlights Efficiency & Output 95% AFUE across all sizes (AB‑80, AB‑120, AB‑155) Modulation range from 80 to 155 MBH input; AB‑120 net-rated at 97 MBH, DOE output 112 MBH weil-mclain.com +14 weil-mclain.com +14 afsupply.com +14 Heat Exchanger Large-diameter, single-tube 316L stainless steel Flat-plate DHW side and combined heating loop; 80 & 120 combi models include internal 3-speed Grundfos circulator thefurnaceoutlet.com +10 weil-mclain.com +10 afsupply.com +10 Venting & Fuel Options Configurable for direct vent, concentric, or sidewall/roof venting using 3‑in‑1 PVC/CPVC/PP/SS adapter Full factory setup for natural gas; field‑convertible to propane afsupply.com +12 weil-mclain.com +12 powerequipmentdirect.com +12 Controls & Serviceability Digital Honeywell control platform with outdoor reset sensor included Pre-wired plug-in 120 VAC power supply and 24 VAC relay terminals; heavy-gauge insulated jacket, removable panels for easy servicing weil-mclain.ca +15 weil-mclain.com +15 powerequipmentdirect.com +15 Emissions & Certifications South Coast AQMD Low-NOx compliant; ENERGY STAR certified; EPA-certified combi performance; internal condensate trap and neutralizer optional afsupply.com +4 weil-mclain.com +4 weil-mclain.com +4 ???? Contractor Benefits Compact Footprint – Wall-mountable (≈28″ high), ideal for mechanical closets and existing systems with limited space Ease of Installation – Includes mounting bracket, sensors, plug-in cord, circulator; all internal components accessible for maintenance System Flexibility – Compatible with baseboard, radiant, or panel heat systems; common relay terminal strip allows easy zone control integration ⚠️ Installation & Application Guide Must be mounted on a gas-rated wall structure; requires sealed combustion venting per local code. Must include condensate drain connection and optional neutralizer when PVC/CPVC venting is used. Calibration of turndown, water pressure, and DHW flow rate is required during commissioning. Suitable for retrofits or new builds demanding combined space heating and potable water output up to ~4 GPM ecomfort.com +14 weil-mclain.com +14 weil-mclain.com +14 afsupply.com +1 weil-mclain.com +1 weil-mclain.ca . Summary The AquaBalance AB‑120‑C offers a robust, dual-function solution with condensing efficiency, compact design, and modern controls—streamlining installations where space savings and integrated DHW are priorities. Perfectly suited for contractors aiming to deliver high-performance heating systems in residential and small commercial environments.