Immersion Rod Copper tube element with long lasting nickel plating for longer element for quick heating Rod To use this appliance, fill up a bucket with water and immerse the metallic rod of the heater into it like you hang clothes on hangers. Then put the plug into the socket and put the switch on. The latest models are also found to have an indicator to make the process even easier and user-friendly. Its 3 pin Plug & also it is ISI marked. Wellberg immersion water heater is a basic water heating appliance that can heat up a full bucket of water in just a couple of minutes.