The Bosch Greenstar gas condensing boiler is compact and highly-efficient, boasting 95% AFUE efficiency, the company says.

U.S. Boiler Co.’s Alta line of condensing boilers and combi-boilers features next-generation gas-adaptive technology that provides the shortest installation time and lowest operating costs.

AMP condensing, water-tube boilers by Thermal Solutions are AHRI-certified at 97% efficiency and offer 10:1 turndown. 

Navien NFB-H condensing fire tube boilers feature turndown ratios up to 15:1, an advanced user interface with intuitive text display and easy-to-use Setup Wizard, 2" venting up to 65', and built-in hardware to connect a boiler system pump, 3 zone pumps or 3 zone valves.

The FTX1000 boiler has a maximum input of 999,000 Btu/h and a stainless-steel fire tube heat exchanger.

The Rinnai I-Series condensing boiler simultaneously delivers domestic hot water and central heating to serve home heating needs.

Navien NFB-C commercial condensing fire tube boilers have all key components in-house designed and manufactured

U.S. Boiler Co. expanded its Alta line of condensing, gas-adaptive boilers with a larger combi size and several heat-only models.

On the older hydronic systems, replacing the existing boiler with a new one was pretty straightforward. The installer connected the new boiler to the existing flue, piping and electric. The newer high-efficiency boilers are much different and require some additional planning.

The Instinct Floor Boiler comes loaded with features such as: a low loss header with dirt & air separator, Tsnyc Wi-Fi connectivity (for easy trouble shooting), an all stainless steel fire tube heat exchanger, industry leading 5+ GPM DHW and peace-of-mind 10 year warranty.