Heating element

An electric heater to heat a flow of a fluid, comprising:

• at least one heating element defining an axially elongate heating block having first and second lengthwise ends;
• a plurality of longitudinal bores or channels extending internally through the axially elongate heating block and being open at each respective first and second lengthwise end;
• the at least one heating element consisting of an electrically conducting material for active resistance heating or more than one electrically conducting material for active resistance heating;
• and
• first and second terminals provided at the heating block for connection to a current supply,
• wherein the electrically conducting material or the more than one electrically conducting material is/are selected from the group of an iron-chromium-aluminium alloy;
• a nickel-chromium alloy, a copper-nickel based alloy or iron-nickel-chromium alloy, and an intermetallic material,
• wherein a plurality of heating elements are assembled together as the heating block, each heating element comprising the material and having a bore or channels that in part defines the bores or channels of the heating block, and
• wherein the plurality of longitudinal bores or channels extending internally through the axially elongated heating block include channels formed in gap regions between external facing surfaces between neighbouring heating elements.