The NOBLE Fire Tube Combi Boiler is designed for residential applications and offers three models ranging from 110,000-199,999 Btuh. The boiler features easy installation and serviceability, true instantaneous response time, and a user-friendly interface.

If a boiler is not serviced regularly, products of combustion may build up on the heat exchanger, which may reduce heat transfer and result in lower energy efficiency and less comfort.

The standards, which were set by the Energy Independence and Security Act (EISA) in 2007 and implemented Sept. 1, 2012, required residential gas hot water boilers to meet a minimum AFUE of 82 percent; gas steam boilers, 80 percent; oil hot water boilers, 84 percent; and oil steam boilers, 82 percent.

Bosch has replaced its Buderus GC124 residential gas-fired boiler with the new precision cast GC144 boiler, a compact Energy Star-compliant boiler capable of delivering best-in-class 85 percent AFUE.