907.2 Installation — 2025 California Mechanical Code

Wall furnaces shall be installed in accor dance with the manufacturer’s installation instructions. Wall

furnaces installed in or attached to combustible material shall be listed for such installation. [NFPA 54:10.25.2.1]

907.2.1 Vented Wall Furnaces. Vented wall furnaces connected to a Type B-W gas vent system listed only for a single story shall be installed only in single-story buildings or the top story of multistory buildings. Vented wall furnaces connected to a Type B-W gas vent system listed for installation in multistory buildings shall be permitted to be installed in single-story or multistory buildings. Type B-W gas vents shall be attached directly to a solid header plate that serves as a firestop at that point and that

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shall be permitted to be an integral part of the vented wall furnace, as illustrated in Figure 907.2.1. The stud space in which the vented wall furnace is installed shall be ventilated at the first ceiling level by installation of the ceiling plate spacers furnished with the gas vent. Firestop spacers shall be installed at each subsequent ceiling or floor level penetrated by the vent. [NFPA 54:10.25.2.2]

907.2.2 Direct Vent Wall Furnaces. Direct vent wall

furnaces shall be installed with the combustion air intake

terminal outdoors. [NFPA 54:10.25.2.3]

907.2.3 Panels, Grilles, and Access Doors. Panels, grilles, and access doors that are required to be removed for normal servicing operations shall not be attached to the building. For additional information on the venting of wall furnaces, see Section 802.0. [NFPA 54:10.25.2.4]

For SI units: 1 inch = 25.4 mm

FIGURE 907.2.1

INSTALLATION OF TYPE B-W GAS VENTS FOR

VENTED WALL FURNACES

[NFPA 54: FIGURE 10.25.2.2]