for Heating Systems in 20th Century Buildings A local private school conducts annual maintenance checks on their steam heating system during the Christmas Holidays when the students all go home. Their goal is to ensure the components of their steam heating system are functioning correctly before the students return for the cold season from December to February. Overview This schools steam powered heating system is comprised of over 400 Steam Traps spread out over multiple buildings. It took an SDT Ultrasound Technician two days to complete the survey using their SDT340. Their final report indicated that 64% of the traps were functioning correctly, 15% were out of operation, 3% had failed open, another 3% had failed closed, 15% of the traps were beginning to show early signs of impending failure.