The present study examines, through a behavioral survey, the self-reported intentions of consumers in Greece, Portugal and Spain, in relation to a residential hybrid system that offers heating/cooling and domestic hot water (DHW); the system combines ground source heat pumps, solar thermal panels and thermal energy storage. A positive attitude concerning the adoption intention of the system has been recorded, while the results on Willingness to Pay (WTP) and acceptable payback period reveal that there is a potential market for the hybrid system in the three countries. The analysis indicates that consumers' intentions are similar among the three countries, with the only statistical significant difference occurring between Spain and Portugal on the subject of WTP for the system. The socioeconomic factors that are identified to have an effect on consumers' intentions in relation to the hybrid system are gender, income, educational level, occupation, past investments in thermal energy systems and percentage of income spent on household energy needs; the corresponding residence characteristics include location, building type, dwelling size, year of construction and existing system for space heating and DEW. The study's findings can contribute to the broader understanding of consumers' behavior concerning the adoption of residential heating/cooling and DHW systems. (C) 2019 Published by Elsevier Ltd.