U.S. Boiler’s 95% AFUE K2 Firetube boiler features a stainless-steel vertical fire-tube heat exchanger and is available in six sizes from 85-270 MBH. A combi version also is available (155 MBH). All models can be wall-hung and feature 5:1 modulation. Additional contractor-friendly features include a 3-in-1 vent connection, top or bottom supply/return/gas connections, a split voltage junction box with fused connection boards and a full-height side access panel. The unit comes with a free three-year parts and limited labor warranty, with registration within 90 days of installation.

U.S. Boiler. www.usboiler.net