The Bosch Greenstar gas condensing boiler is compact and highly-efficient, boasting 95% AFUE efficiency, the company says. Available in heating-only and combi-versions, the Greenstar boiler comes in wall-hung and floor-standing models to fit the needs of any application. The unit is insulated for ultra-quiet operation and features a fully-modulating fan to maximize efficiency, as well as an advanced Aluminum-Silicon alloy heat exchanger for increased flexibility. The Bosch Greenstar is built to last and requires minimal servicing, Bosch adds.