Bosch Greenstar condensing boilers are ENERGY STAR-certified as energy efficient. As of 2015, eight Greenstar models were certified. Certified products have passed third-party testing at laboratories approved by the U.S. Environmental Protection Agency.
In addition to pre-certification testing, ENERGY STAR products, including boilers, may be tested annually throughout the product's manufacturing life to ensure efficiency standards continue to be met.
Since the inception of the ENERGY STAR program in 1992, the EPA has gradually increased the requirements for products to receive certification. In addition to boilers, products in over 65 categories, from televisions to windows, can receive ENERGY STAR certification.