The Vaillant fan is the device that pushes fresh air into the combustion chamber and allows the gas to be burned correctly. It also removes the remaining burnt gas after the combustion process is complete. The boiler has safety parameters in place to make sure no gas can be passed through to the main burner if the fan has ceased functioning.
Supplier part number is 0020035220
Technical specification
Compatible WithecoTEC PLUS 415, ecoTEC PLUS 418, ecoTEC PLUS 428 and ecoTEC PLUS 438Supplier Part Number0020035220Brand NameVaillant