Chapter 3 — GENERAL REGULATIONS
306.1 General. Heating appliances shall be equipped with
California Mechanical Code (Title 24, Part 4) · 2025 edition · updated 2026-09-10 · California
Italicized text is a California amendment to the model code, as printed in the official publication.
a listed device or devices that will shut off the fuel supply to the main burner or burners in the event of pilot or ignition failure. Liquefied petroleum gas-air-burning heating appli
GENERAL REGULATIONS
ances shall be equipped with a listed automatic device or devices that will shut off the flow of gas to the pilot in the event of ignition failure.
Exception: The listed shutoff devices shall not be required on range or cooking tops, log lighters, lights, or other openburner manually operated appliances, or listed appliances not requiring such devices and specific industrial appliances as approved by the Authority Having Jurisdiction.
Heating appliances whose manual fuel controls are not readily accessible from the main portion of the building being heated shall be equipped with remote controls.
Forced-air and gravity-type warm air furnaces shall be equipped with a listed air outlet temperature limit control that cannot be set for temperatures exceeding 250°F (121°C). Such controls shall be located in the bonnet or plenum, within 2 feet (610 mm) of the discharge side of the heating element of gravity furnaces or in accordance with the conditions of listing.
Electric duct heaters shall be equipped with an approved automatic reset air outlet temperature limit control that will limit the outlet air temperature to not exceed 200°F (93°C). The electric elements of the heater shall be equipped with fusible links or a manual reset temperature limit control that will prevent outlet air temperature in excess of 250°F (121°C).
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Ask AI about this code▸Contents — California Mechanical Code (Title 24, Part 4)
- Chapter 1 — GENERAL CODE PROVISIONS
- Chapter 2 — DEFINITIONS
▸Chapter 3 — GENERAL REGULATIONS
Overview- 301.1 Applicability. This chapter covers general requirements …
- 301.2 Approval. Equipment or appliance shall be approved
- 301.3 Design of Equipment. The installer or contractor
- 301.4 Electrical Connections. For equipment regulated
- 301.5 Oil-Burning Appliances. The tank, piping, and
- 301.6 Personnel Protection. A metal guard shall be provided ar…
- 301.7 OSHPD 1R. [OSHPD 1R] For OSHPD 1R, refer to
- 302.1 Minimum Standards. Listed pipe, pipe fittings,
- 302.2 Alternate Materials and Methods of Construc-
- 302.3 Alternative Engineered Design. An alternative
- 303.1 Listed Appliances. The installation of equipment
- 303.2 Closet or Alcove Installations. [Not adopted
- 303.3 Unlisted Appliances. Except as otherwise permitted in th…
- 303.4 Anchorage of Appliances. Appliances designed to
- 303.5 Restraining Device. Movement of appliances with
- 303.6 Identification of Equipment. Where more than one
- 303.7 Liquefied Petroleum Gas (LP-Gas) Facilities.
- 303.8 Appliances on Roofs. Appliances on roofs shall be
- 303.9 Avoiding Strain on Gas Piping. Appliances shall
- 303.10 Clearance to Combustible Materials. Appliances and thei…
- 303.11 Installation in Commercial Garages. Appliances installe…
- 303.12 Installation in Aircraft Hangars. Heaters in aircraft h…
- 304.1 General. All appliances shall be located with respect
- 304.2 Sloped Roof. Where equipment or appliances that
- 304.3 Access to Appliances on Roofs. Appliances
- 304.4 Appliances in Attics and Under-Floor Spaces.
- 305.1 Installation in Residential Garages. Appliances
- 305.2 Pit Location. Where excavation is necessary to install
- 305.3 Flood Hazard Areas. For buildings located in flood
- 305.4 Elevator Shaft. Unless required for the functionality
- 305.5 Drainage Pan. Where a water heater is located in an
- 305.6 Outdoor Locations. Appliances installed in outdoor
- 306.1 General. Heating appliances shall be equipped with
- 306.2 Building Automation Systems. [OSHPD 1]
- 307.1 Fuel-Burning Appliances. Fuel-burning heating
- 307.2 Electric Heating Appliances. Electric heating
- 307.3 Heat Pump and Electric Cooling Appliances.
- 307.4 Absorption Units. Absorption units shall bear a permanen…
- 308.1 General. Piping or equipment shall not be so located as
- 309.1 Engineering Practices. Design, construction, and
- 309.2 Concealing Imperfections. It shall be unlawful to
- 309.3 Installation Practices. Mechanical systems shall
- 310.1 Condensate Disposal. Condensate from air washers, air-co…
- 310.2 Condensate Control. Where any equipment or
- 310.3 Condensate Waste Pipe Material and Sizing.
- 310.4 Appliance Condensate Drains. Condensate drain
- 310.5 Point of Discharge. Air-conditioning condensate
- 310.6 Condensate Waste from Air-Conditioning
- 310.7 Female Plastic Connections. Female plastic
- 311.1 Source. A heating or cooling air system shall be provide…
- 311.2 Air Filters. Air filters shall be installed in a heating,
- 311.3 Prohibited Sources. Outside or return air for a heating …
- 311.4 Return-Air Limitations. Return air from one
- 311.5 California Energy Code Requirements for Res-
- 312.1 General. Water supply, sanitary drainage, and backflow p…
- 313.1 General. Piping, tubing, appliances, and appurtenances s…
- 313.2 Material. Hangers, supports, and anchors shall be of
- 313.3 Suspended Piping. Suspended piping or tubing
- 313.4 Alignment. Piping or tubing shall be supported in
- 313.5 Underground Installation. Piping or tubing in the
- 313.6 Hanger Rod Sizes. Hanger rod sizes shall be not
- 313.7 Gas Piping. Gas piping shall be supported by metal
- 314.1 General. Heating, ventilating, and air-conditioning
- 315.1 General. Louvers located in areas within hurricane
- 316.1 General. Piping or tubing passing under or through
- 316.2 Installation. Piping or tubing shall be installed so that
- 316.3 Corrosion, Erosion, and Mechanical Damage.
- 316.4 Protectively Coated Pipe. Protectively coated pipe
- 316.5 Fire-Resistant Construction. Piping, tubing, and
- 316.6 Steel Nail Plates. Plastic piping or tubing, copper
- 316.7 Sleeves. Sleeves shall be provided to protect piping
- 316.8 Firewalls. A pipe sleeve through a firewall shall have
- 316.9 Structural Members. A structural member weakened or impa…
- 316.10 Rodentproofing. Mechanical system shall be constructed …
- 316.11 Metal Collars. In or on buildings where openings
- 317.1 Trenches. Trenches deeper than the footings of a
- 317.2 Tunneling and Driving. Tunneling and driving shall
- 317.3 Open Trenches. Excavations required to be made for
- 317.4 Excavations. Excavations shall be completely backfilled …
- 318.1 Applicability. This part is applicable to health facil-
- 318.2 Services/Systems and Utilities. Refer to Section
- 319.1 Requirements for Hospitals and Optional Serv-
- 319.2 Requirements for Skilled Nursing, Intermedi-
- 320.1 Requirements for Hospitals and Optional Serv-
- 320.2 Requirements for Skilled Nursing, Intermedi-
- 320.3 Requirements for Outpatient Facilities and
- 320.4 Telephone and Technology Equipment Centers.
- 320.5 Psychiatric Services. [OSHPD 1, 1R, 2, 4 & 5] For
- 321.1 (Does not apply to OSHPD 3 surgical clinic.) All heat-
- 321.2 All heating equipment and fans necessary to maintain
- 321.3 Cooling equipment necessary to maintain temperature
- 321.4 Equipment necessary for humidification of the areas
- 321.5 All supply, return, and exhaust fans required to maintain
- 321.6 All control components, control systems and fire and
- 321.7 Alarms for airborne infection isolation rooms and pro-
- 322.0 Sensitive Areas or Rooms. [OSHPD 1, 2, 3 (Sur-
- 322.1 The following conditions shall be met for sensitive
- 325.0 Alternate Source of Power for Safe Tempera-
- Chapter 4 — VENTILATION AIR
- Chapter 5 — EXHAUST SYSTEMS
- Chapter 6 — DUCT SYSTEMS
- Chapter 7 — COMBUSTION AIR
- Chapter 8 — CHIMNEYS AND VENTS
- Chapter 9 — INSTALLATION OF SPECIFIC APPLIANCES
- Chapter 10 — BOILERS AND PRESSURE VESSELS
- Chapter 11 — REFRIGERATION
- Chapter 12 — HYDRONICS
- Chapter 13 — FUEL GAS PIPING
- Chapter 14 — PROCESS PIPING
- Chapter 15 — SOLAR ENERGY SYSTEMS
- Chapter 16 — STATIONARY POWER PLANTS
- Chapter 17 — GEOTHERMAL ENERGY SYSTEMS AND AMBIENT TEMPERATURE…
- Chapter 18 — REFERENCED STANDARDS
- Appendix A — RESIDENTIAL PLAN EXAMINER REVIEW FORM FOR HVAC SY…
- Appendix B — PROCEDURES TO BE FOLLOWED TO PLACE GAS EQUIPMENT …
- Appendix C — INSTALLATION AND TESTING OF OIL (LIQUID) FUEL-FIR…
- Appendix D — FUEL SUPPLY: MANUFACTURED/MOBILE HOME PARKS AND R…
- Appendix E — SUSTAINABLE PRACTICES
- Appendix F — SIZING OF VENTING SYSTEMS AND OUTDOOR COMBUSTION …
- Appendix G — EXAMPLE CALCULATION OF OUTDOOR AIR RATE
- Appendix H — PROFESSIONAL QUALIFICATIONS
- Appendix I — INDOOR HORTICULTURAL FACILITIES
- Appendix J — CLEAN AIR DELIVERY