This dataset provides data for a new heat pump unit intended to provide heating, cooling and hot water to a hotel and using CO2 as the working fluid. The heat pump was installed in mid-2018 in a hotel located in a touristic area in North Italy and open nearly all over the year. The unit can benefit from groundwater as a heat source or heat sink. The heat pump features a two-phase multi-ejector as an expansion device. An original two-evaporator layout is implemented, where the first one is gravity driven and the second one is ejector driven. It is fully equipped with measurement instruments, data acquisition system and cloud data storage developed and tailored for the unit. The unit was developed, instrumented, installed and monitored within the H2020 MultiPACK the project, which aims at building confidence in integrated heating, ventilation, air conditioning and refrigeration packages based on CO2 technology in high energy-demanding buildings. In this dataset, operational parameters and performance data will be presented, related to winter season, thus to heating and domestic hot water service.