... toppest manufacturer of 58*1800 solar bolier,solar water heater with CE,Solar Keymark,CCC 1.Products series ... when exposed to sun without water: 250°C, 2.5 hours to boiling point if using single tube. ... holes for exhaust port, overflow, water inlet and outlet, electric heater is optionWelding:Argon arc weldingFastening pieces: ... of 58*1800 solar bolier,solar water heater with CE,Solar Keymark,CCC