How is the output of an immersion heater boiler typically controlled?

The output of an immersion heater boiler is typically controlled by turning the power supply to the electric elements on and off. This method allows for precise regulation of the temperature and the heating process. By using a simple on-off control system, the immersion heater can maintain the desired temperature of the water, reacting to the demand for heat. This method is energy efficient and straightforward, making it a common choice for electric heating applications.

Controlling the output by adjusting the water flow rate or changing fuel types does not apply to immersion heaters specifically, as they are normally designed to operate with a fixed flow rate and are exclusively electric. While a mechanical thermostat can be used in some systems to regulate temperature, it functions in conjunction with the on-off control of the power supply; therefore, it is not the primary method of control for immersion heaters.