Lochinvar’s CREST with Hellcat Combustion Technology commercial boiler is available in eight models ranging from 999,000-6,000,000 Btu/h. Boasting up to 96.2% thermal efficiency and up to a 25:1 turndown ratio, the unit features RealTime O2 Trim which includes Feed Forward, Feed Back, Commissioned Trim and Learned Trim. The O2 sensor combined with Lochinvar’s Smart Touch control allows the unit to adapt to its environment.