ncy HorizonTM HZ40E Gas Fireplace EFTA00301424 REQUIREMENTS MA Code - CO Detector (for the State of Massachusetts only) 5.08: flodlfleatIons to NFPA-54. Chapter 10 (2) Revise 10.8.3 by adding the following additional requirements: (a) For all side wall horizontally vented gas fueled equipment insta