Electrodes
An electrode on a central heating boiler is a component that plays a crucial role in the ignition process of the boiler’s burner. It is responsible for creating a spark or electric arc that ignites the fuel-air mixture, initiating the combustion process necessary for heat generation.

The electrode typically consists of two metal rods or wires positioned in close proximity to each other. One electrode, known as the “ignition electrode” or “spark electrode,” is connected to a high-voltage ignition system, while the other electrode, known as the “ionization electrode” or “flame sensing electrode,” is in contact with the flame.

The main functions of the electrodes in a central heating boiler are as follows:

Ignition: The ignition electrode is responsible for producing a high-energy spark or electric arc that ignites the fuel-air mixture within the combustion chamber. It generates a strong electrical discharge, creating a controlled spark between the electrodes to initiate the combustion process.
Flame Sensing: The ionization electrode, also known as the flame sensing electrode, is positioned close to the burner flame. Once the combustion is established, it detects the presence of the flame by sensing the ionized particles generated by the burning fuel. The ionization current flows between the flame and the electrode, providing feedback to the boiler’s control system to confirm that the flame is present and stable.

The combination of the ignition electrode and the ionization electrode ensures the safe and reliable ignition and monitoring of the burner flame in the central heating boiler. If the ionization electrode does not detect a flame, it can signal the control system to shut off the fuel supply to prevent the release of unburned fuel or the buildup of potentially dangerous gases.

It is important to keep the electrodes clean and free from any deposits or debris that may hinder their performance. Regular maintenance, including cleaning or replacing the electrodes as recommended by the manufacturer, helps ensure proper ignition and flame detection in the boiler.

If there are any issues with the electrodes, such as a weak spark, poor flame sensing, or frequent ignition failures, it is recommended to consult a qualified heating engineer or technician. They have the expertise to inspect and service the electrodes, ensuring the safe and efficient operation of the central heating boiler.