The Glow-worm ignition lead assembly part is located near the electrodes. Usually, there are two types of electrodes are ignition electrodes and flame-sensing electrodes. The ignition electrode creates the spark that starts off combustion within the appliance. The flame-sensing electrodes are responsible for detecting whether there is a flame present in the burner. This is an important safety device that makes sure the boiler isn't still supplying gas without a flame.

Brand Name	Glow-worm