The Viessmann 7828718 Ignition & Ionization Electrode Block is a replacement ignition and flame-sensing component designed for compatible Viessmann gas-fired boilers and heating systems. It generates the electrical spark required to ignite the gas-air mixture and monitors the flame to confirm proper combustion. This integrated electrode block supports reliable startup and continuous b... https://www.partshnc.com/7828718-viessmann-ign-ioniz-electrode-block