What Is a Heater Coil?
A heater coil is a device used to heat water or air. Typically electric, the heater coil acts like a large resistor, and as the electric current flows through it, it begins to heat up. The resistance wire used in common household toasters is the same type of wire used in a heater coil. The amount of heat produced by the heater coil is controlled by a rheostat switch. Many appliances, such as hot water heaters, electric clothes dryers and electric ovens, all use some type of heater coil to produce heat.