The Pilot Assembly is located in the Saunier Duval boilers just in front of the main burner, they consist of an electrode, thermocouple and pilot injector. Its sole purpose is to light the pilot light and ensure it remains lit.
Saunier Duval S900601 Burner

Part: S900601

Price: £126.80
Saunier Duval S203212 Burner

Part: S203212

Price: £74.71
Saunier Duval Burner 0020097272

Part: 0020097272

Price: £53.81