Nos Star

Nos Star
What is the connection diagram of star and delta connection for an electric heater?

I have an old electric heater 6 nos heating elements. Each heating element is 2Kw. and connect each end with a phase and neutral 220vA / c.. Now I want to change this boiler / heater for 3 phases. 3phase wiring is available on the board. type of connection is a star or delta connection right? and what is the difference? And what be the diagram?

If you are a 220/400v 220v heaters nd that their supply is then connected in pairs in parallel and then connect the three parallel groups star, including a neutral to the point star.