... heater with shell, consist of aluminum or copper, transflux type or immerging type. Various coating, such as Teflon, ceramic paint, or oxygenation ... several parts can be used for larger power. PTC as heating element, it fits for high safety, slap-up product. Using to ... heat quiet waterIt is long time to heat the water in whole tankUsed to maintain temperature of waterBottom heaterHeater put under ...