Description

Weil-McLain AB-120H AquaBalance Series 2 120,000 BTU Heat-Only Condensing Gas Boiler

Weil-McLain is a leading North American Brand of hydronic comfort heating systems for residential, commercial and institutional buildings, since 1881. Contractors, engineers, architects, homeowners, and facility managers alike rely on Weil-McLain boilers for their comfort heating needs. Installed in homes, offices, schools, restaurants, hotels, and other facilities throughout North America, the Weil-McLain brand is among the most trusted and often used in the building industry.

Features

Compact design to increase placement options
Heavy gauge insulated jacket provides quiet operation
Contractor-friendly removable sides
Pre-wired, plug-in ready electrical design
Commercial grade 120V power 6′ cord with 3 prong plug
24 VAC thermostat relay, fuse protected with prewired terminal strip
Honeywell control with digital display
Wall mounting bracket and hardware included
Unique „3-in-1“ vent adapter readily accepts PVC, CPVC, SS, or PP vent materials
Multiple vent options includes direct vent, 2 pipes or concentric, through roof or sidewall
Strategically placed sensors used instead of additional bulky boiler controls

What Our Experts Think

Efficient condensing design: The Weil‑McLain AB‑120H AquaBalance Series 2 120,000 BTU Heat‑Only Condensing Gas Boiler uses condensing technology to extract more heat from combustion, lowering fuel costs compared to non‑condensing units.

Heat‑only focus: Built to deliver space heating only, it pairs well with a separate domestic hot‑water system, keeping design simple and efficient.

Quiet, dependable performance: Smooth combustion and well‑engineered components provide consistent warmth and stable operation.

Durable and service‑friendly: Corrosion‑resistant heat exchanger and accessible service points make maintenance easier and help extend service life.

Product Q&A

What does “heat‑only” mean?
The boiler provides space heating only — it does not produce domestic hot water; a separate water heater or indirect tank is required for DHW.

What fuel does it use?
Natural gas; a licensed HVAC tech can install a propane conversion kit if LP gas is needed.

Where is this best used?
Ideal for single‑family homes or light commercial systems with separate hot water sources that need efficient hydronic heating.

How efficient is it?
Condensing design boosts heat extraction from exhaust gases, improving overall system efficiency and lowering operating cost.

Maintenance Tips

Annual professional check: Have a licensed HVAC technician inspect and tune the boiler before the heating season — burner, heat exchanger, condensate system, and controls.

Clear condensate lines: Ensure condensate drains and traps are clear and properly pitched to avoid clogs or freeze issues.

Monitor pressure & water levels: Maintain correct boiler pressure and verify expansion tank function.

Clean vents & intakes: Keep air intake and exhaust terminations free of debris to ensure safe operation.

Inspect for leaks: Periodically check valves, joints, and piping for signs of water or gas leaks.

Maintain water quality: Use recommended inhibitors and schedule periodic system flushing to reduce scale and extend component life.

Weil-McLain AB-120H AquaBalance Series 2 120,000 BTU Heat-Only Condensing Gas Boiler-Schneller Versand

Description