The primary constituents of an immersion heater include: Heating element: Typically a nichrome or copper wire on an insulating core that generates heat upon electrical current flow. Insulating sleeve: Safeguards the heating element and averts short circuits with water. Metal sheath: Encloses the heating element and insulation, commonly copper or stainless steel to resist corrosion. Thermostat: Regulates temperature by cycling the heater on and off. Terminal box: Houses electrical connections and offers a secure wire entry. Protective casing: The external structure shielding the complete unit.