The Viessmann 7817324 Ionization Electrode with Gasket is a genuine replacement ignition and flame-sensing component designed for compatible Viessmann gas-fired boilers and HVAC heating systems. It detects the presence of a stable burner flame by monitoring the ionization current, ensuring safe and efficient burner operation while preventing unsafe gas flow if no flame is detected. https://www.partshnc.com/7817324-viessmann-ionization-electrode-wgskt