... five toppest manufacturer of 58*1800 solar bolier,solar water heater with CE,Solar Keymark,CCC 1.Products series ModelCapacity(L ... holes for exhaust port, overflow, water inlet and outlet, electric heater is optionWelding:Argon arc weldingFastening pieces:stainless steel screw5.solar ... five toppest manufacturer of 58*1800 solar bolier,solar water heater with CE,Solar Keymark,CCC