• Fully condensing high-mass firetube boiler
  • Large capacity, industrial design
  • 4,000 to 12,000 MBH
  • Standard less than 20 ppm NOx


Ideal for variable flow primary systems, the ClearFire®-LC (CFLC) is a high-mass, fully condensing hydronic boiler, capable of variable-flow pumping, allowing for maximum operating efficiency in a variety of system applications. The revolutionary larger capacity design allows the most effective installation by using fewer units as opposed to banks of smaller boilers, thus reducing capital cost, complexity, and maintenance.

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  • Product Overview
  • Related Resources
  • Applications
  • Fully condensing with up to 98% efficiency and 5:1 turndown
  • Ultra-low emissions
  • No minimum return water temperature for maximum efficiency and reliability
  • Dual temperature returns for system design flexibility
  • Up-front capital cost is reduced by installing fewer larger-capacity boilers
  • Fully integrated system includes boiler, burner, and controls for multiple lead/lag configuration


The ClearFire®–LC integrates Cleaver-Brooks leading heat exchanger, burner and control technology into a large capacity condensing boiler solution. The CFLC's integrated premix burner and linkageless control, work together to provide full modulation, ultra-low emissions and optimum turndown. By combining our proven extended heating surface tube designs, our patented AluFer® tubes and exclusive spiral tubes in a true counter flow arrangement, the CFLC delivers the capacity, efficiency and reliability previously considered unattainable. When you are the industry leader, the only way to stay there is to continuously innovate. Many of our competitors claim to be innovators, but no one invests more energy and resources into research and product development. The CFLC is the latest in Cleaver-Brooks product advancements that define their category.


Controls Strategies for Maximizing Condensing Boiler System Efficiency →

Learn basic boiler control strategies and staging methods to maximize boiler operating efficiencies.

Why Ultra-High Turndown Is Bad For Hydronic Condensing Boilers →

Learn about optimized system efficiency, why matching boiler and pump turndown is critical to maintain the delta T and maximize efficiency.

Lowest Total Cost of Ownership Video →

Alufer Technology Video →

Dual Return Advantage Video →

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