Worcester Electrodes
Usually, there are two different types of electrode, Ignition electrodes and flame sensing electrodes. The Ignition electrode makes the spark that begins combustion within the burner The flame sensing electrodes are responsible for monitoring whether there is a flame present in the burner. This is an important task and if the flame is not detected the boiler knows to re-attempt ignition.

Worcester Bosch 8716121817 Set Of Electrodes - CDi/Greenstar/Highflow
Part No: 1020146 MPN: 8716121817

Worcester Bosch 8737709581 Electrode With Spring - GR8300IW/GR8700IW
Part No: 2249118 MPN: 8737709581

Worcester Bosch 87161427520 Ignition Electrode - Danesmoor/Heatslave
Part No: 1018483 MPN: 87161427520