The Benefits at a Glance - All the benefits of a Vitodens 100 boiler, plus on-demand domestic hot water (DHW) with CombiPLUS Kit. - DHW at the snap of your fingers all day long! Up to 3.6 GPM. ** - Energy-efficient and low-cost due to on-demand indirect-fired DHW production. - Reduced energy waste with fully-modulating input from boiler. - Space-saving and lightweight wall-mount design. More compact than any other hot water heater. - Virtually silent DHW production. - Easy installation with all piping and electrical connections included. - Quality you can count on! Stainless steel heat exchanger, built-in pressure bypass and 150 psig working pressure rating. - Reliable and even DHW supply with built-in DHW temperature and flow sensors. - Complete space / DHW heating management by boiler control, powerful built-in 3-speed pump and diverting valve. - Great fit for apartments, condos, cottages, single-family homes, or installs where space is at a premium.