Abstract: A smart boiler system serving boilers each equipped with sensor/s monitoring an aspect of boiler water heating functionality and a local controller collecting sensor data and communicating data to remote server, the system comprising a central server in data communication with said data network and including a processor having operational mode/s including a maintenance-needs-detection operational mode operative to scan data stored in a boiler data repository, on occasion, and to rank boilers accordingly, in terms of predetermined criterion defining maintenance need/s, and provide “push” output/s indicating a subset of boilers currently ranking high in terms of predetermined criterion defining at least one maintenance need.