Bosch 7-738-100-002 Greenstar Combi 100 (ZWB28) Wall Condensing Boiler, Heating and Tankless Hot Water, Input 100 MBHBosch Water Heater 7 738 100 002 The Greenstar comes in a floor standing or wall mounted option that will provide reliable and efficient heating for a townhouse, condo, apartment, single or multi family home. Available as a heat only boiler for use with a hot water tank, or as a combi model for heating integrated with tankless domestic hot water (DHW) At Bosch we design and manufacture all of our key components in house, our assembly process is