Brand names are a starting point.

A model family is not an exact specification

Manufacturers reuse family names across outputs, fuels, voltages and regional configurations. Begin with the heating job, then write down the complete model number from the current submittal or manual. Check who will install and service it locally, how the sales channel affects warranty coverage, and whether the utility and equipment pad meet the documented requirements. The brand desks below use that sequence to keep a recognizable logo from substituting for fit.