Description

Weil-McLain Ultra Series 4 399,000 BTU 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

Cast aluminum coated heat exchanger
Designed to operate in low temperature condensing applications
Outdoor reset and domestic hot water priority
Modulates with 5:1 turn-down ratio
High grade stainless steel burner features quiet operation
U-Control gives the power for easy set-up and maintenance
Multiple set-up and zone options
System sensing recognizes system and outdoor temperatures
Temperature management for up to three different set-points
Control multiple boilers from a single control panel
Standard screen messages provide service alerts and maintenance reminders

What Our Experts Think

Top‑tier efficiency: The Weil‑McLain Ultra Series 4 399,000 BTU Condensing Gas Boiler delivers industry‑leading condensing performance (typically up to ~95% AFUE), maximizing heat output while minimizing fuel costs.

High heating capacity: With 399,000 BTU/h, this model powers large homes, multifamily buildings, and light commercial spaces requiring substantial hydronic heat.

Smooth, quiet operation: Advanced burner and heat‑transfer design provide stable combustion with reduced noise and more even heat delivery.

Durable & service‑friendly: Corrosion‑resistant heat exchanger and accessible service points support long life and easier maintenance for technicians.

Product Q&A

What type of boiler is this?
A high‑efficiency condensing gas boiler that uses a secondary heat exchanger to extract extra energy from combustion exhaust.

Where is it best used?
Ideal for large residential properties, multifamily units, schools, offices, and light commercial facilities with significant heating demand.

What heating systems does it support?
Works with hydronic baseboard, radiant floor systems, fan coils, and other hot‑water distribution loops.

What fuel does it use?
Natural gas (propane conversion kits may be available from Weil‑McLain via a qualified HVAC technician).

Does it need special venting?
Yes — condensing boilers typically use PVC/CPVC or polypropylene venting because of lower exhaust temperatures and condensate handling.

Maintenance Tips

Annual professional service: Have a licensed HVAC technician inspect and tune the boiler before each heating season — checking the burner, heat exchanger, controls, and combustion performance.

Check condensate drainage: Make sure condensate outlets and trap lines are clear and properly pitched to avoid buildup or freeze issues.

Monitor system pressure: Maintain proper boiler pressure and expansion tank condition as recommended.

Clean intake & exhaust terminations: Keep vents free of debris and obstruction for safe combustion airflow.

Inspect for leaks: Check around valves, fittings, and piping periodically for signs of water or gas leaks.

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

Weil-McLain Ultra Series 4 399,000 BTU Condensing Gas Boiler-Schneller Versand

Description