An improved tube liquid heater is composed of many metal heat sinks in overlap connection mounted in a shell, a heater is set between two adjacent heat sinks with a metal electrode at either side of each heater isolated from the heat sink by insulated material. The said metal sink is strip tabular hollow pipe. The inner cavity of each heat sink forms a through pipe with a joint at each end connecting to the adjacent heat sink, so the inner cavities of all the heat sinks connect to a through pipe with liquid inlet and exit at the two ends characterizing that the said joint connects the ends of the two heat sinks axially or in radial and outside of the heater is designed with many connectors conncting with each pair of metal electrodes and power. |