1.SABS,COC,SRCC,EN12975,CE,ISO9001,ISO14001 2.Three years warranty &15 years after sale service 3. 7 to 15 days delivery time Working principle:when the diffeference of collector temperature and tank temperature gets to the set value, the circulation system will start work. It will transmit the solar energy from solar collector to the tank.a. Module design, arbitrary combination, harmonize with ...