Preferred Utilities Receives UL Listing to Fire Biodiesel for API Burner and UL Listing/CSA Certification for Comet Burner. New UL Listings highlight quality and sustainability. Read the Press Release Here — DANBURY, CT Preferred Utilities Manufacturing Corporation has received UL certification for its Advanced Performance Inject-Aire (API) Low NOx Burner and both UL and CSA certification for its Comet Burner. They […]