U.S. Boiler’s 95% AFUE K2 Firetube boiler features a stainless-steel vertical firetube heat exchanger and is available in six sizes from 85-270 mbh. A combi version is also available (155 MBtuh). All models can be wall-hung and feature 5:1 modulation. Additional contractor-friendly features include a three-in-one 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