Lennox X8798 Ballast 318973 401 installing this genuine York part installing this genuine York part is critical for restoring factory standard performance and preventing the excessive noise or shaft oscillation associated with worn or aftermarket mounting supports A technician can verify failure using a multimeter to check for an open circuit or high resistance the X8798 maintains the integrity of the PCO (Photocatalytic Oxidation) process by delivering consistent electrical current to the UVA lamps this ballast ensures the high output performance required to neutralize airborne contaminants and microorganisms within the HVAC airstream