CPC · California Plumbing Code
What are the venting requirements and when must vents be inspected?
Inspectors must examine any chimney, vent, or part installed under a permit after it’s put in place and before it’s covered or concealed (this is the explicit CPC requirement in §503.1). The CPC also contains a water‑heater vent rule at §504.2, but the provided files did not include that section’s full text — consult the CPC or your local building department for the detailed venting specs.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The California Plumbing Code requires that chimneys, vents, or parts thereof authorized by a permit be inspected after installation and before being covered or concealed — see § 503.1. The code also contains a water‑heater vent provision at § 504.2, but the full text of § 504.2 was not included in the files you provided; consult § 504.2 directly for the specific water‑heater vent requirements.
The single most important rule: inspect any chimney or vent (or any part of it) that the permit covers after it’s installed and before you cover or conceal it (see § 503.1).
Requirements in detail
Inspection timing (what triggers an inspection)
- The Authority Having Jurisdiction must inspect chimneys, vents, or parts thereof after they are installed and before they are covered or concealed — § 503.1. This is a pre‑concealment inspection requirement; no appliance or vent component may be concealed prior to approval.
Scope (what kinds of vents are covered in the CPC materials you provided)
- Chimneys, vents or parts thereof installed under a permit are covered by § 503.1 (inspection timing).
- The code includes broader venting rules across Chapter 9 (general venting for sanitary systems) and Chapter 5/9/8 (venting of appliances and water heaters), but the specific text of § 504.2 (Vent) was not available in the uploaded files. I cannot quote or assert the missing text.
Decision‑relevant dimensions (quick look-up table)
| Question you need to answer | Required value / action | Code reference |
|---|---|---|
| When must a vent or chimney be inspected? | After installation and before it is covered or concealed | § 503.1 |
| Is there a separate water‑heater vent rule in the CPC? | Yes — § 504.2 (text not contained in provided files; consult the code) | § 504.2 |
| Where to find general venting rules for appliances? | Chapter 5 (water heaters) and appliance venting sections (e.g., § 509.x) | Chapter/sections on venting |
| Are there separate inspection rules for smoke/heat vents? | Yes — fire code requires routine inspection/testing of smoke & heat vents (see Fire Code § 910.5) | Fire Code § 910.5 |
How inspectors typically apply § 503.1
- Inspector arrives after vent/chimney installation but before drywall/roofing/other concealment, verifies vent routing, clearances, connector attachments, supports, and that materials match the permit. The code's plain requirement is timing — the exact inspection checklist is set by the Authority Having Jurisdiction and other CPC provisions (venting chapters).
Exceptions & special cases
- Smoke and heat vents and mechanical smoke removal systems are covered under the California Fire Code; those have their own inspection schedules (e.g., mechanically operated smoke/heat vents — annual inspection and operational testing not less than every 5 years) and are not governed by § 503.1’s pre‑concealment language. See Fire Code § 910.5.1 for the specific inspection frequency for smoke/heat vents.
- The CPC includes multiple venting types and appliance‑specific venting provisions (e.g., gas vent sizing, multistory venting, direct‑vent appliances). Those appliance and sizing rules appear elsewhere (e.g., § 509.x and Chapter 9) and can affect what the inspector checks during the required pre‑concealment inspection.
Common mistakes
- Covering or concealing a vent or chimney component before the required inspection. The code explicitly prohibits concealment prior to inspection/approval under § 503.1.
- Assuming all vent inspections follow the same schedule — smoke/heat vents in the Fire Code have different periodic inspection/testing rules. Don’t conflate the CPC pre‑concealment inspection with ongoing maintenance schedules in the Fire Code.
- Relying on a permit alone without verifying that the installed vent matches the permit documents and the appliance/manufacturer instructions (venting type, clearances, connector sizing). The inspector should confirm installed materials and configuration.
- Expecting § 504.2’s content here — the uploaded files show § 504.2 exists, but its full text was not part of the documents provided, so do not rely on this article for the specific technical requirements in § 504.2.
Worked example — concrete scenario
Scenario: You install a gas water heater with a new vent connector and a short chimney chase. The installer obtains a permit and installs the vent and chimney liner. Before the contractor covers the chase with drywall and closes the roof flashing, the permit requires an inspection.
Step‑by‑step under the CPC:
- Schedule the inspection after the vent/chimney is installed but before covering. This is exactly what § 503.1 requires — the inspection is to be made after installation and before the vent or part thereof is covered or concealed. The inspector will verify routing, connectors, clearances, supports, and that the installation matches the permit.
- If the installation involves appliance‑specific venting details (e.g., connector sizing, gas vent type), the inspector will compare the installation to the applicable venting rules in Chapter 5/8/9 or § 509.x as needed. See the appliance venting sections for those technical checks.
- Only after the inspector approves the vent/chimney may the contractor cover the chase or proceed with final concealment. No concealment prior to approval.
Related provisions
- § 503.1 — Inspection of chimneys or vents (pre‑concealment inspection requirement).
- § 504.2 — Vent (water‑heater vent provision exists in the CPC TOC; full text not included in provided files).
- Chapter 9 (Vents) — general venting rules for sanitary drainage systems and vent types.
- § 509.3 and related § 509.x — appliance venting, minimum performance and installation (appliance vent rules and sizing are in these sections).
- Fire Code § 910.5 — maintenance and testing schedules for smoke and heat vents (separate inspection/testing rules).
Code references
Grounded in the retrieved California Plumbing Code — click a citation to read the verbatim passage:
CPC § 910.5 High relevance — show source text
910.5 Maintenance and testing. Maintenance and testing of smoke and heat vents and mechanical smoke removal systems shall be in accordance with Sections 910.5.1 and 910.5.2. A written record of inspection, testing and maintenance that includes the date, identification of personnel involved, any unsatisfactory result, corrective action taken and replaced parts shall be maintained on the premises.
910.5.1 Smoke and heat vents. Smoke and heat vents shall be maintained in an operative condition. Inspection, testing and maintenance shall be in accordance with NFPA 204 except as follows:
- Mechanically operated smoke and heat vents shall be inspected annually and operationally tested not less than every 5
years. 2. Gravity dropout smoke and heat vents shall be inspected annually. 3. Fused, damaged or painted fusible links shall be replaced.
910.5.2 Mechanical smoke removal systems. Mechanical smoke removal systems shall be maintained in accordance with NFPA 204 and the equipment manufacturer’s instructions except as follows:
- Systems shall be inspected and operationally tested annually.
- Testing shall include the operation of all system components, controls and ancillary equipment, such as makeup air openings.
- A written schedule for routine maintenance and operational testing shall be established and testing shall be conducted in accordance with the schedule.
SECTION 911—EXPLOSION CONTROL
911.1 General. Explosion control shall be provided in the following locations:
- Where a structure, room or space is occupied for purposes involving explosion hazards as identified in Table 911.1.
- Where quantities of hazardous materials specified in Table 911.1 exceed the maximum allowable quantities in Table 5003.1.1(1).
Such areas shall be provided with explosion (deflagration) venting, explosion (deflagration) prevention systems or barricades in accordance with this section and NFPA 68, NFPA 69 or NFPA 495 as applicable. Deflagration venting shall not be utilized as a means to protect buildings from detonation hazards.
TABLE 911.1—EXPLOSION CONTROL REQUIREMENTSf Col2 Col3 Col4 MATERIAL CLASS EXPLOSION CONTROL METHODS EXPLOSION CONTROL METHODS MATERIAL CLASS Barricade
constructionExplosion (deflagration) venting or
explosion (deflagration) prevention systemsHazard Category Hazard Category Hazard Category Hazard Category Combustible dustsa — Not required Required Cryogenic fluids Flammable Not required Required 2025 CALIFORNIA FIRE CODE 9-67
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
FIRE PROTECTION AND LIFE SAFETY SYSTEMS
|TABLE 911.
CPC § 910.4.3.1 Medium relevance — show source text
910.4.3.1 Makeup air. Makeup air openings shall be provided within 6 feet (1829 mm) of the floor level. Operation of makeup air openings shall be manual or automatic. The minimum gross area of makeup air inlets shall be 8 square feet per 1,000 cubic feet per minute (0.74 m [2] per 0.4719 m [3] /s) of smoke exhaust.
910.4.4 Activation. The mechanical smoke removal system shall be activated by manual controls only.
910.4.5 Manual control location. Manual controls shall be located where they are able to be accessed by the fire service from an exterior door of the building and separated from the remainder of the building by not less than 1-hour fire barriers constructed in accordance with Section 707 of the California Building Code or horizontal assemblies constructed in accordance with Section 711 of the California Building Code, or both.
910.4.6 Control wiring. Wiring for operation and control of mechanical smoke removal systems shall be connected ahead of the main disconnect in accordance with Section 701.12E of the California Electrical Code and be protected against interior fire exposure to temperatures in excess of 1,000°F (538°C) for a period of not less than 15 minutes.
910.4.7 Controls. Where building air-handling and mechanical smoke removal systems are combined or where independent building air-handling systems are provided, fans shall automatically shut down in accordance with the California Mechanical Code . The manual controls provided for the smoke removal system shall have the capability to override the automatic shutdown of fans that are part of the smoke removal system.
910.5 Maintenance and testing. Maintenance and testing of smoke and heat vents and mechanical smoke removal systems shall be in accordance with Sections 910.5.1 and 910.5.2. A written record of inspection, testing and maintenance that includes the date, identification of personnel involved, any unsatisfactory result, corrective action taken and replaced parts shall be maintained on the premises.
910.5.1 Smoke and heat vents. Smoke and heat vents shall be maintained in an operative condition. Inspection, testing and maintenance shall be in accordance with NFPA 204 except as follows:
- Mechanically operated smoke and heat vents shall be inspected annually and operationally tested not less than every 5
years. 2. Gravity dropout smoke and heat vents shall be inspected annually. 3. Fused, damaged or painted fusible links shall be replaced.
910.5.2 Mechanical smoke removal systems. Mechanical smoke removal systems shall be maintained in accordance with NFPA 204 and the equipment manufacturer’s instructions except as follows:
- Systems shall be inspected and operationally tested annually.
- Testing shall include the operation of all system components, controls and ancillary equipment, such as makeup air openings.
- A written schedule for routine maintenance and operational testing shall be established and testing shall be conducted in accordance with the schedule.
SECTION 911—EXPLOSION CONTROL
911.1 General. Explosion control shall be provided in the following locations:
- Where a structure, room or space is occupied for purposes involving explosion hazards as identified in Table 911.1.
- Where quantities of hazardous materials specified in Table 911.1 exceed the maximum allowable quantities in Table 5003.1.1(1).
CPC § 710.11 Medium relevance — show source text
Where the preceding requirements are met and the vent, after leaving the sump, is combined with vents from fixtures discharging into the sump, the size of the combined vent need not exceed that required for the total number of fixtures discharging into the sump. No vent from an air-operating sewage ejector shall combine with other vents. 710.11 Air Tanks. Air tanks shall be so proportioned as to be of equal cubical capacity to the ejectors connected in addition to that in which there shall be maintained an air pressure of not less than 2 pounds per foot (lb/ft) (3 kg/m) of height the sewage is to be raised. No water-operated ejectors shall be permitted. 710.12 Grinder Pump Ejector. Grinder pumps shall be permitted to be used. 710.12.1 Discharge Piping. The discharge piping shall be sized in accordance with the manufacturer’s installation instructions and shall be not less than 1 [1] ⁄ 4 inches (32 mm) in diameter. A check valve and fullwaytype shutoff valve shall be located on the discharge line. 710.13 Macerating Toilet Systems and Pumped Waste Systems. Fixtures shall be permitted to discharge to a macerating toilet system, or pumped waste system shall be permitted as an alternate to a sewage pump system where approved by the Authority Having Jurisdiction. Such systems shall comply with ASME A112.3.4/CSA B45.9 and shall be installed in accordance with the manufacturer’s installation
instructions.
710.13.1 Sumps. The sump shall be watertight and gastight. 710.13.2 Discharge Piping. The discharge piping shall be sized in accordance with manufacturer’s instructions and shall be not less than [3] ⁄ 4 of an inch (20 mm) in diameter. The developed length of the discharge piping shall not exceed the manufacturer’s instructions. A check
174 2025 CALIFORNIA PLUMBING CODE
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SANITARY DRAINAGE
valve and fullway-type shutoff valve shall be located within the discharge line or internally within the device.
710.13.3 Venting. The plumbing fixtures that discharge into the macerating device shall be vented in accordance with this code. The sump shall be vented in accordance with the manufacturer’s instructions, and such vent shall be permitted to connect to the fixture venting.
711.0 Suds Relief.
711.1 General. Drainage connections shall not be made into a drainage piping system within 8 feet (2438 mm) of a vertical to horizontal change of direction of a stack containing suds-producing fixtures. Bathtubs, laundries, washing machine standpipes, kitchen sinks, and dishwashers shall be considered suds-producing fixtures. Where parallel vent stacks are required, they shall connect to the drainage stack at a point 8 feet (2438 mm) above the lowest point of the drainage stack.
Exceptions:
(1) Single-family residences.
(2) Stacks receiving the discharge from less than three stories of plumbing fixtures.
712.0 Testing.
CPC § 905.1 Medium relevance — show source text
905.1 Grade . . . . . . . . . . . . . . . . . . . . . .190
905.2 Horizontal Drainage Pipe . . . . . . .190
905.3 Vent Pipe Rise . . . . . . . . . . . . . . .190
905.4 Roof Termination . . . . . . . . . . . . .190
905.5 Location of Opening . . . . . . . . . . .190
905.6 Common Vertical Pipe . . . . . . . . .190
906.0 Vent Termination . . . . . . . . . . . . .190
906.1 Roof Termination . . . . . . . . . . . . .190
906.2 Clearance . . . . . . . . . . . . . . . . . . .190
906.3 Use of Roof . . . . . . . . . . . . . . . . .190
906.4 Outdoor Installations . . . . . . . . . . .190
906.5 Joints . . . . . . . . . . . . . . . . . . . . . .190
906.6 Lead . . . . . . . . . . . . . . . . . . . . . . .190
906.7 Frost or Snow Closure . . . . . . . . .190
907.0 Vent Stacks and Relief Vents . . . .190
907.1 Drainage Stack . . . . . . . . . . . . . . .190
907.2 Yoke Vent . . . . . . . . . . . . . . . . . . .190
908.0 Wet Venting . . . . . . . . . . . . . . . . .190
908.1 Vertical Wet Venting . . . . . . . . . . .190
908.2 Horizontal Wet Venting for a Bathroom Group . . . . . . . . . . . . . .191
909.0 Special Venting for Island Fixtures . . . . . . . . . . . . . . . . . . . . .191
909.1 General . . . . . . . . . . . . . . . . . . . . .191
910.0 Combination Waste and Vent
Systems . . . . . . . . . . . . . . . . . . . .191
910.1 Where Permitted . . . . . . . . . . . . . .191
910.2 Approval . . . . . . . . . . . . . . . . . . . .191
910.3 Vents . . . . . . . . . . . . . . . . . . . . . .191
910.4 Connections and Size . . . . . . . . .191
910.5 Vertical Waste Pipe . . . . . . . . . . .191
910.6 Cleanouts . . . . . . . . . . . . . . . . . . .191
910.7 Fixtures . . . . . . . . . . . . . . . . . . . . .191
911.0 Circuit Venting . . . . . . . . . . . . . . .191
911.1 Circuit Vent Permitted . . . . . . . . .191
911.2 Circuit Vent Size and
Connection . . . . . . . . . . . . . . . . . .192
CPC § 2025 Medium relevance — show source text
Chapter 7 Sanitary Drainage.
This chapter regulates the design and installation of sanitary drainage systems to ensure they will work as intended. Drainage piping should not be oversized nor undersized, and constructed of approved materials to guard against fouling, deposit of solids, clogging, and with cleanouts so arranged that the pipes may be readily cleaned. The purpose of the sanitary drainage system is to remove effluent discharged from plumbing fixtures and other equipment to an approved point of disposal, such as a public sanitary system or private sewage disposal system.
The basics of a sanitary drainage system include public and private sewage disposal; selection of materials; installation of the building drain and sewer; joining methods for pipe and fittings; drainage fixture units for sizing the drainage system; sumps and ejectors; vent sizing and length of vents; and testing.
Chapter 8 Indirect Wastes.
Chapter 8 regulates indirect waste connections that are required for plumbing fixtures and plumbing appliances dealing with food preparation, dishwashing, potable liquids, and similar equipment. An indirect connection prevents sewage from backing up into a fixture or appliance, thus providing protection against potential health hazards. The waste pipe discharges through an air gap or air break into a waste receptor or standpipe. The protection in the form of an air gap is necessary when the contamination is a potential health hazard or cross connection with the potable water system. Where there is no possibility of contaminating the potable water (nonpotable discharge), the indirect waste pipe may connect in the form of an air break. This method is often preferred to prevent splashing. In addition, health care facilities and special wastes must be protected from contamination that may result from the connection to the drainage system. The waste must be treated to prevent any damage to the piping or sewage treatment process. Waste receptors are sized and designed to prevent splashing and allow for peak discharge conditions.
Chapter 9 Vents.
Chapter 9 regulates the material, design, and installation of vents. A vent system is a pipe or pipes installed in a drainage system that provide a flow of air to and from the system to ventilate it, provide a circulation of air to eliminate trap siphonage, and reduce back-pressure and vacuum surge. In addition, vents provide the rapid and silent flow of waste without exposing occupants of the building to any sewer gases. Proper installation of vents is crucial, as a telltale sign that there is a problem in the drain and vent system is related to the elevation of the horizontal portion of the venting. Venting is not limited to sanitary drainage systems. Venting methods are applicable to other drainage systems such as those for chemical waste, graywater waste, and clear water waste. Sizing the venting system is directly tied to the design of the drainage system. For example, the velocities in the drainage system and its peak flow rates affect the diameters in the venting system. Where the vertical distance between a fixture outlet and trap is excessive, velocities in the entire drainage system will be greater than those in the vent sizing table. All venting methods in this chapter are categorized as either dry vents or wet vents. Vent stacks, stack vents, branch vents, island vents, relief vents, and individual vents are dry vents. Wet vents (horizontal or vertical), circuit vents, combination drain and vents are versions of “wet venting” in which the vent is wetted by drainage flow.
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CPC § 501.1 Medium relevance — show source text
Table 501.1(1) Water Heaters . . . . . . . . . . . . . . . .83
501.2 California Energy Code Water Heating System Requirements . . . . . . . . . . . . . . . . .83
502.0 Permits . . . . . . . . . . . . . . . . . . . . . .83
502.1 General . . . . . . . . . . . . . . . . . . . . . .83
503.0 Inspection . . . . . . . . . . . . . . . . . . . .83
503.1 Inspection of Chimneys or Vents . . .83
503.2 Final Water Heater Inspection . . . .83
504.0 Water Heater Requirements . . . . . .83
504.1 Location . . . . . . . . . . . . . . . . . . . . .83
Table 501.1(2) First Hour Rating . . . . . . . . . . . . . .83
504.2 Vent . . . . . . . . . . . . . . . . . . . . . . . .84
504.3 Clearance . . . . . . . . . . . . . . . . . . . .84
504.4 Pressure-Limiting Devices . . . . . . .84
504.5 Temperature-Limiting Devices . . . .84
504.6 Temperature, Pressure, and Vacuum Relief Devices . . . . . . . . .84
504.7 Lead Content . . . . . . . . . . . . . . . . .84
505.0 Oil-Burning and Other Water Heaters . . . . . . . . . . . . . . . . . . . . . .84
505.1 Water Heaters . . . . . . . . . . . . . . . .84
505.2 Safety Devices . . . . . . . . . . . . . . . .84
505.3 Oil-Fired Water Heaters . . . . . . . . .84
505.4 Indirect-Fired Water Heaters . . . . .84
506.0 Air for Combustion and
Ventilation . . . . . . . . . . . . . . . . . . . .84
506.1 General . . . . . . . . . . . . . . . . . . . . . .84
506.2 Indoor Combustion Air . . . . . . . . . .85
506.3 Indoor Opening Size and Location . . . . . . . . . . . . . . . . . . . . .85
506.4 Outdoor Combustion Air . . . . . . . . .85
506.5 Combination Indoor and
Outdoor Combustion Air . . . . . . . . .87
506.6 Engineered Installations . . . . . . . . .87
506.7 Mechanical Combustion Air Supply . . . . . . . . . . . . . . . . . . . . . . .87
506.8 Louvers, Grilles, and Screens . . . .87
506.9 Combustion Air Ducts . . . . . . . . . . .87
507.0 Appliance and Equipment Installation Requirements . . . . . . . .88
507.1 Dielectric Insulator . . . . . . . . . . . . .88
CPC § 507.20 Medium relevance — show source text
507.20 Gas Appliance Pressure Regulators . . . . . . . . . . . . . . . . . . .89
507.21 Bleed Lines for Diaphragm-Type Valves . . . . . . . . . . . . . . . . . . . . . . .89
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TABLE OF CONTENTS
507.22 Combination of Appliances and Equipment . . . . . . . . . . . . . . . .90
507.23 Installation Instructions . . . . . . . . . .90
507.24 Protection of Outdoor
Appliances . . . . . . . . . . . . . . . . . . .90
507.25 Accessibility for Service . . . . . . . . .90
507.26 Clearance to Combustible
Materials . . . . . . . . . . . . . . . . . . . . .90
508.0 Appliances on Roofs, in Attics or Under-Floor Spaces . . . . . . . . . .90
508.1 General . . . . . . . . . . . . . . . . . . . . . .90
508.2 Installation of Appliances on Roofs . . . . . . . . . . . . . . . . . . . . .90
508.3 Appliances on Roofs . . . . . . . . . . .90
508.4 Appliances in Attics and Under-Floor Spaces . . . . . . . . . . . .91
509.0 Venting of Appliances . . . . . . . . . . .91
509.1 Listing . . . . . . . . . . . . . . . . . . . . . . .91
509.2 Connection to Venting Systems . . .91
509.3 Minimum Safe Performance . . . . . .91
509.4 Type of Venting System to be Used . . . . . . . . . . . . . . . . . . . . .92
Table 509.4 Type of Venting System to be Used . . . . . . . . . . . . . . . . . . .92
509.5 Masonry, Metal, and Factory-Built Chimneys . . . . . . . . .93
509.6 Gas Vents . . . . . . . . . . . . . . . . . . . .94
Table 509.6.1 Roof Slope Heights . . . . . . . . . . . .95
509.7 Single-Wall Metal Pipe . . . . . . . . . .97
Table 509.7.3.4(1) Clearances for Connectors . . . . . . .97
Table 509.7.3.4(2) Reduction of Clearances with Specified Forms of Protection . . . .99
509.8 Through-the-Wall Vent Termination . . . . . . . . . . . . . . . . . .100
509.9 Condensation Drain . . . . . . . . . . .100
509.10 Vent Connectors for
Category I Appliances . . . . . . . . .100
Table 509.8.1 Through-the-Wall Direct-Vent Termination Clearances . . . . . . . .101
Table 509.10.1.3 Minimum Thickness for
CPC § 422.1 Medium relevance — show source text
422.1 Fixture Count . . . . . . . . . . . . . . . . .67
422.2 Separate Facilities . . . . . . . . . . . . .68
422.3 Fixture Requirements for Special Occupancies . . . . . . . . . . .68
422.4 Toilet Facilities Serving Employees and Customers . . . . . .68
422.5 Toilet Facilities for Workers . . . . . .69
422.6 Water Closet Compartment . . . . . .69
422.7 Urinal Partitions . . . . . . . . . . . . . . .69
422.8 Cosmetology . . . . . . . . . . . . . . . . .69
422.9 Cosmetology Establishments . . . . .69
422.10 Commissaries Serving Mobile Food Preparation Units . . . . . . . . .69
422.11 Employee Lavatories in Food Establishments . . . . . . . . . . .69
Table 422.1 Minimum Plumbing Facilities . . . . .70
Table 4-1 Occupant Load Factor
[BSC and DSA-SS] . . . . . . . . . . . .75
Table 4-2 Minimum Plumbing Facilities
[OSHPD 1, 2, 3, 4 & 5] . . . . . . . . .76
CHAPTER 5 WATER HEATERS . . . . . . . . . . . .81
501.0 General . . . . . . . . . . . . . . . . . . . . . .83
501.1 Applicability . . . . . . . . . . . . . . . . . . .83
Table 501.1(1) Water Heaters . . . . . . . . . . . . . . . .83
501.2 California Energy Code Water Heating System Requirements . . . . . . . . . . . . . . . . .83
502.0 Permits . . . . . . . . . . . . . . . . . . . . . .83
502.1 General . . . . . . . . . . . . . . . . . . . . . .83
503.0 Inspection . . . . . . . . . . . . . . . . . . . .83
503.1 Inspection of Chimneys or Vents . . .83
503.2 Final Water Heater Inspection . . . .83
504.0 Water Heater Requirements . . . . . .83
504.1 Location . . . . . . . . . . . . . . . . . . . . .83
Table 501.1(2) First Hour Rating . . . . . . . . . . . . . .83
504.2 Vent . . . . . . . . . . . . . . . . . . . . . . . .84
504.3 Clearance . . . . . . . . . . . . . . . . . . . .84
504.4 Pressure-Limiting Devices . . . . . . .84
504.5 Temperature-Limiting Devices . . . .84
504.6 Temperature, Pressure, and Vacuum Relief Devices . . . . . . . . .84
504.7 Lead Content . . . . . . . . . . . . . . . . .84
CPC § 0.293 Medium relevance — show source text
For SI units: 1000 British thermal units per hour = 0.293 kW
- Dual purpose water heaters shall be installed in accordance with this code and the manufacturer’s installation instructions.
501.2 California Energy Code Water Heating System Requirements. [CEC] See California Energy Code Section 110.3 for additional mandatory requirements for all service water heating systems, and 150.0(n) for additional mandatory requirements for residential service water heating systems.
502.0 Permits.
502.1 General. It shall be unlawful for a person to install, remove, or replace or cause to be installed, removed, or replaced a water heater without first obtaining a permit from the Authority Having Jurisdiction to do so.
TABLE 501.1(1)
WATER HEATERS
For SI units: 1000 British thermal units per hour = 0.293 kW
- Dual purpose water heaters shall be installed in accordance with this code and the manufacturer’s installation instructions.
503.0 Inspection.
503.1 Inspection of Chimneys or Vents. This inspection shall be made after chimneys, vents, or parts thereof, authorized by the permit, have been installed and before such vent or part thereof has been covered or concealed.
503.2 Final Water Heater Inspection. This inspection shall be made after work authorized by the permit has been installed. The Authority Having Jurisdiction will make such inspection as deemed necessary to be assured that the work has been installed in accordance with the intent of this code.
No appliance or part thereof shall be covered or concealed until the same has been inspected and approved by the Authority Having Jurisdiction.
504.0 Water Heater Requirements.
504.1 Location. Water heater installations in bedrooms and
bathrooms shall comply with one of the following [NFPA 54:10.27.1]:
(1) Water heater shall be of the direct-vent type. [NFPA 54:10.27.1(2)]
(2) Fuel-burning water heaters shall be permitted to be installed in a closet located in the bedroom or bathroom provided the closet is equipped with a listed, gasketed door assembly and a listed self-closing device. The selfclosing door assembly shall meet the requirements of Section 504.1.1. The door assembly shall be installed with a threshold and bottom door seal and shall meet the requirements of Section 504.1.2. Combustion air for such installations shall be obtained from the outdoors in accor dance with Section 506.4. The closet shall be for the
exclusive use of the water heater.
504.1.1 Self-Closing Doors. Self-closing doors shall swing easily and freely, and shall be equipped with a self-closing device to cause the door to close and latch each time it is opened. The closing mechanism shall not have a hold-open feature.
504.1.2 Gasketing. Gasketing on gasketed doors or frames shall be furnished in accordance with the published listings of the door, frame, or gasketing material manufacturer.
TABLE 501.1(2) FIRST HOUR RATING [1]
CPC § 12.7.4.4 Medium relevance — show source text
[NFPA 54:12.7.4.4] 509.6.3 Gas Vents Serving Appliances on More than One Floor. Where a common vent is installed in a multistory installation to vent Category I appliances located on more than one floor level, the venting system shall be designed and installed in accordance with engineering methods. Crawl spaces, basements, and attics shall be considered as floor levels. [NFPA 54:12.7.5.1]
509.6.3.1 Occupiable Space. All appliances connected to the common vent shall be located in rooms separated from occupiable space. Each of these rooms shall have provisions for an adequate supply of combustion, ventilation, and dilution air that is not supplied from occupiable space. [NFPA 54:12.7.5.2] (See Figure 509.6.3.1)
FIGURE 509.6.3.1
PLAN VIEW OF PRACTICAL SEPARATION
METHOD FOR MULTISTORY GAS VENTING
[NFPA 54: FIGURE A.12.7.5.2]
509.6.3.2 Multistory Venting System. The size of the connectors and common segments of multistory venting systems for appliances listed for use with a Type B double-wall gas vent shall be in accordance with Table 510.2(1), provided all of the following apply:
(1) The available total height ( H ) for each segment of a multistory venting system is the vertical distance between the level of the highest draft hood outlet or flue collar on that floor and the centerline of the next highest interconnection
tee.
(2) The size of the connector for a segment is determined from the appliance’s gas input rate and available connector rise and shall not be smaller
than the draft hood outlet or flue collar size.
(3) The size of the common vertical vent segment, and of the interconnection tee at the base of that segment, is based on the total appliance’s gas input rate entering that segment and its available total height. [NFPA 54:12.7.5.3]
509.6.4 Support of Gas Vents. Gas vents shall be supported and spaced in accordance with the manufacturer’s installation instructions. [NFPA 54:12.7.6]
509.6.5 Marking. In those localities where solid and liquid fuels are used extensively, gas vents shall be per
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WATER HEATERS
manently identified by a label attached to the wall or ceiling at a point where the vent connector enters the gas vent. The label shall read: “This gas vent is for appliances that burn gas. Do not connect to solid or liquid fuel-burning appliances or incinerators.” The Authority Having Jurisdiction shall determine whether its area constitutes such a locality. [NFPA 54:12.7.7] 509.7 Single-Wall Metal Pipe. Single-wall metal pipe shall be constructed of galvanized sheet steel not less than 0.0304 of an inch (0.7722 mm) thick or of other approved, noncombustible, corrosion-resistant material. [NFPA 54:12.8.1]
CMC § 2025 Medium relevance — show source text
Systems that carry nonabrasive exhaust, such as smoke, moderate abrasives such as sawdust, and high abrasives such as manganese or acid vapors use product-conveying ducts. Part II provides the minimum fire safety requirements related to the design, installation, inspection, and maintenance of grease-type operations, such as cooking, for both fuel-gas and solid fuel. Cooking produces a significant amount of smoke, fumes, vapors, heat, and other pollutants. Therefore, acceptable kitchen ventilation is necessary to prevent fires from the build-up of grease and to provide the occupants protection from smoke, unpleasant odors, pollutants, and dangerous gases. There are two types of exhaust hoods (Type I and Type II) used in commercial kitchen applications.
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FORMAT OF THE UNIFORM MECHANICAL CODE
Type I hoods are intended to be installed above equipment or appliances that generate grease or smoke. Type II hoods are intended to be installed above equipment or appliances that generate steam, vapor, heat, or odors and do not generate grease or smoke.
Chapter 6 Duct Systems. Chapter 6 regulates requirements for ducts and plenums that are portions of a heating, cooling, ventilation, or exhaust system. This chapter contains material and installation requirements for metal, gypsum, factory-made, flexible, and plastic ducts. It also contains provisions for duct insulation, dampers, fire protection, and automatic shutoff for the building’s air distribution system. It is worth noting that exhaust ducts are regulated by Chapter 5, and combustion air ducts are regulated by Chapter 7.
Chapter 7 Combustion Air. Chapter 7 regulates combustion air requirements for ventilation and dilution of flue gases for appliances installed in buildings. Fuel-gas appliances not regulated by chapter include direct vent appliances and Type I clothes dryers. Makeup air requirements for Type I clothes dryers are located in Chapter 5. Chapter 7 provides acceptable methods for supplying satisfactory combustion air to ensure proper combustion. Combustion air can be supplied by using indoor combustion air or by introducing the air from the outdoors.
Combustion is the rapid oxidation of fuel to release energy. The oxygen required to release the energy from the fuel normally comes from the air. Incomplete combustion of fuel occurs when inadequate oxygen is provided to the appliance. Combustion is needed to provide ventilation cooling for the casing and internal controls. When a lack of oxygen occurs, some of the carbon is not oxidized, and carbon monoxide forms.
Chapter 8 Chimneys and Vents. Chapter 8 regulates the installation, design, and construction of venting systems for fuel-burning appliances. The provisions addressed within this chapter follow procedures an installer would use to design or evaluate a venting system. Many requirements apply to the design and construction of venting systems, chimneys, installation of gas vents, and the sizing of venting system for a Category I appliance. Sizing venting systems require rigorous engineering calculations. However, the venting sizing requirements and sizing tables in this chapter already perform the calculations for the benefit of the end user.
Combustion appliances produce products of incomplete combustion, including potentially harmful carbon monoxide (CO). It is desirable to vent these products to the outdoors. Although the gas is clean-burning fuel, the products of combustion must not be allowed to collect within a building.
CPC § 2025 Medium relevance — show source text
The waste must be treated to prevent any damage to the piping or sewage treatment process. Waste receptors are sized and designed to prevent splashing and allow for peak discharge conditions.
Chapter 9 Vents.
Chapter 9 regulates the material, design, and installation of vents. A vent system is a pipe or pipes installed in a drainage system that provide a flow of air to and from the system to ventilate it, provide a circulation of air to eliminate trap siphonage, and reduce back-pressure and vacuum surge. In addition, vents provide the rapid and silent flow of waste without exposing occupants of the building to any sewer gases. Proper installation of vents is crucial, as a telltale sign that there is a problem in the drain and vent system is related to the elevation of the horizontal portion of the venting. Venting is not limited to sanitary drainage systems. Venting methods are applicable to other drainage systems such as those for chemical waste, graywater waste, and clear water waste. Sizing the venting system is directly tied to the design of the drainage system. For example, the velocities in the drainage system and its peak flow rates affect the diameters in the venting system. Where the vertical distance between a fixture outlet and trap is excessive, velocities in the entire drainage system will be greater than those in the vent sizing table. All venting methods in this chapter are categorized as either dry vents or wet vents. Vent stacks, stack vents, branch vents, island vents, relief vents, and individual vents are dry vents. Wet vents (horizontal or vertical), circuit vents, combination drain and vents are versions of “wet venting” in which the vent is wetted by drainage flow.
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FORMAT OF THE UNIFORM PLUMBING CODE
Chapter 10 Traps and Interceptors.
Chapter 10 regulates the material, design, and installation of traps, interceptors, and separators. Traps are required on drainage type plumbing fixtures and must be self-scouring without interior partitions. Interceptors, on the other hand, are designed to control what goes down a drain. Interceptors are used to keep harmful substances from entering the sanitary drainage system, such as grease, sand, oil and other materials. The retained materials need periodic removal to maintain efficiency and function of the separating device. The capacity of an interceptor is based on retention and flow rate. There are many types of interceptors that are used at beauty salons, hospitals, meat, fish or foul packaging, refineries, repair garages, gas stations, car washing facilities, various plants, factories, and processing sites. The designer of the building is responsible for locating interceptors with the expectation for the frequency of maintenance, ease of cleaning and floor space for equipment.
Chapter 11 Storm Drainage.
Chapter 11 regulates the removal of stormwater from roofs, yards, paved areas, and similar areas. The objective of storm drainage systems is to provide a conduit or channel through which runoff will be carried from a point of collection to a point of disposal; this protects the property and the public from the uncontrolled flow of runoff and ensures that drains and inlets are adequately sized to receive the volume of runoff that flows to the drains. For the purpose of system design, it’s necessary to specify the duration of a selected storm.
CPC § 803.0. Medium relevance — show source text
(1) Those listed in Section 803.0.
(2) The effective areas of the vent connector and chimney flue of a venting system serving a single appliance with a draft hood shall be not less than the area
of the appliance flue collar or draft hood outlet or greater than seven times the draft hood outlet area.
(3) The effective area of the chimney flue of a venting system serving two appliances with draft hoods shall be not less than the area of the larger draft hood outlet plus 50 percent of the area of the smaller draft hood outlet or greater than seven times the smaller draft hood outlet area.
(4) Chimney venting systems using mechanical draft shall be sized in accordance with engineering methods.
(5) Other engineering methods. [NFPA 54:12.6.3.1]
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CHIMNEYS AND VENTS
FIGURE 802.5.4
TYPICAL TERMINATION LOCATIONS FOR
CHIMNEYS AND SINGLE-WALL METAL PIPES SERVING
RESIDENTIAL-TYPE AND LOW-HEAT APPLIANCE
[NFPA 54: FIGURE A.12.6.2.1]
802.5.6 Inspection of Chimneys or Vents. This inspection shall be made after chimneys, vents, or parts thereof, authorized by the permit, have been installed and before such vent or part thereof has been covered or concealed.
802.5.7 Inspection of Chimneys. Before replacing an existing appliance or connecting a vent connector to a chimney, the chimney passageway shall be examined to ascertain that it is clear and free of obstructions and shall be cleaned if previously used for venting solid- or liquid-fuel-burning appliances or fireplaces. [NFPA 54:12.6.4.1] 802.5.7.1 Standard. Chimneys shall be lined in accordance with NFPA 211. [NFPA 54:12.6.4.2]
802.5.7.2 Cleanouts. Cleanouts shall be examined and where they do not remain tightly closed when not in use, they shall be repaired or replaced. [NFPA 54:12.6.4.3] 802.5.7.3 Existing Chimney. When inspection reveals that an existing chimney is not safe for the intended application, it shall be repaired, rebuilt, lined, relined, or replaced with a vent or chimney to conform to NFPA 211 and shall be suitable for the appliances to be attached. [NFPA 54:12.6.4.4] 802.5.8 Chimney Serving Appliances Burning Other Fuels. An appliance shall not be connected to a chimney flue serving a separate appliance designed to burn solid fuel. [NFPA 54:12.6.5.1] 802.5.8.1 Gas and Liquid Fuel-Burning Appliances. Where one chimney serves gas appliances and liquid fuel-burning appliances, the appliances shall be connected through separate openings or connected through a single opening where joined by a suitable fitting located as close as practical to the chimney. Where two or more openings are provided into one chimney flue, they shall be at different levels.
CPC § 4.6 Medium relevance — show source text
Considerations are soil density; clearance from obstacles, utilities, and structures; location of bends, and water service locations. Excavations and shoring shall be in accordance with jurisdictional safety requirements. (c) Set Up Fuse the proper length of polyethylene pipe in accordance with ASTM F2620, or ASTM D3261 and fuse the end to a small length that is attached to the pulling head. A rod pusher cable is pushed through the damaged host pipe and attached to the pulling cable, which is then drawn through the pipe. The clevis end of the cable is attached to the pulling head. The pulling equipment is then set up according to the manufacturer’s instructions.
(d) Pulling Pull the pulling head through. Once the pull is done, complete the connection to the existing piping.
4.6 Cleanouts
4.6.1 Plug Each cleanout fitting for cast-iron pipe shall consist of a cast-iron or brass body and an approved plug. Each cleanout for galvanized wrought-iron, galvanized steel, copper, or brass pipe shall consist of a brass plug as specified in Table 1, or a standard weight brass cap, or an approved ABS or PVC plastic plug, or an approved stainless-steel cleanout or plug. Plugs shall have raised square heads or approved countersunk rectangular slots. 4.6.2 Approved Each cleanout fitting and each cleanout plug, or cap shall be of an approved type.
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4.6.3 Watertight and Gastight
Cleanouts shall be designed to be watertight and gastight.
5 Testing and Inspection Requirements
5.1 Media
The piping of the building sewer shall be tested with water. The Authority Having Jurisdiction shall be permitted to require the removal of cleanouts, etc., to ascertain whether the pressure has reached all parts of the system.
5.2 Water Test
The system shall be tested by plugging the end of the building sewer at its points of connection to the public sewer or private sewage disposal system and completely filling the building sewer with water from the lowest to the highest point thereof.
5.3 Inspections
The completed piping shall be internally inspected by camera unless waived by the Administrative Authority.
TABLE 1
CLEANOUTS (See Section 4.6.1)
NPS SIZE OF CLEANOUT
(inches)THREADS PER INCH 1.5 1.5 11.5
21.5 11.5
2.52.5 8
32.5 8
4 & larger3.5 8 Note: For SI units: 1 inch = 25 mm
Uniform Plumbing Code References
The following sections of the 2024 Uniform Plumbing Code apply.
105.2 Required Inspections
105.2.2 Other Inspections
105.3 Testing of Systems
301.2 Minimum Standards
309.0 Workmanship
312.0 Protection of Piping, Materials, and Structures
CPC § 11.0 Medium relevance — show source text
11.0 - 1.11.11_|||X|||||||||||||||||||||| |1.13.0||||||||||||||||||||X||||| |Division II - Scope and
Administration||||||||||||||||||||||||| |101.0||||||||||X|X|X||X|X|||||||||| |102.0||||||||||X|X|X||X|X|||||||||| |103.0||||||||||X|X|X||X|X|||||||||| |104.2 Items 1 & 2||||X|X|||||||||||||||||||| |104.3.1||||||||||X|X|X||X|X|||||||||| |104.4.3.1|X|||||||||||||||||||||||| |105.0||||||||||X|X|X||X|X||||||||||This state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.0.
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CHAPTER 1
ADMINISTRATION
DIVISION I
CALIFORNIA ADMINISTRATION
1.1.0 General.
1.1.1 Title. These regulations shall be known as the Califor- nia Plumbing Code, may be cited as such and will be referred to herein as “this code.” The California Plumbing Code is Part 5 of thirteen parts of the official compilation and publi- cation of the adoption, amendment, and repeal of plumbing regulations to the California Code of Regulations, Title 24, also referred to as the California Building Standards Code. This part incorporates by adoption the 2024 Uniform Plumb- ing Code of the International Association of Plumbing and Mechanical Officials with necessary California amendments.
1.1.2 Purpose. The purpose of this code is to establish the minimum requirements to safeguard the public health, safety and general welfare through structural strength, means of egress facilities, stability, access to persons with disabilities, sanitation, adequate lighting and ventilation, and energy con- servation; safety to life and property from fire and other haz- ards attributed to the built environment; and to provide safety to fire fighters and emergency responders during emergency operations.
1.1.3 Scope. The provisions of this code shall apply to the construction, alteration, movement, enlargement, replace- ment, repair, equipment, use and occupancy, location, main- tenance, removal, and demolition of every building or structure or any appurtenances connected or attached to such buildings or structures throughout the State of California.
CPC § 1.1.0 Medium relevance — show source text
CHAPTER 1
ADMINISTRATION
DIVISION I
CALIFORNIA ADMINISTRATION
1.1.0 General.
1.1.1 Title. These regulations shall be known as the Califor- nia Plumbing Code, may be cited as such and will be referred to herein as “this code.” The California Plumbing Code is Part 5 of thirteen parts of the official compilation and publi- cation of the adoption, amendment, and repeal of plumbing regulations to the California Code of Regulations, Title 24, also referred to as the California Building Standards Code. This part incorporates by adoption the 2024 Uniform Plumb- ing Code of the International Association of Plumbing and Mechanical Officials with necessary California amendments.
1.1.2 Purpose. The purpose of this code is to establish the minimum requirements to safeguard the public health, safety and general welfare through structural strength, means of egress facilities, stability, access to persons with disabilities, sanitation, adequate lighting and ventilation, and energy con- servation; safety to life and property from fire and other haz- ards attributed to the built environment; and to provide safety to fire fighters and emergency responders during emergency operations.
1.1.3 Scope. The provisions of this code shall apply to the construction, alteration, movement, enlargement, replace- ment, repair, equipment, use and occupancy, location, main- tenance, removal, and demolition of every building or structure or any appurtenances connected or attached to such buildings or structures throughout the State of California.
1.1.3.1 Non-State-Regulated Buildings, Structures, and Applications. Except as modified by local ordinance pur- suant to Section 1.1.8, the following standards in the Cal- ifornia Code of Regulations, Title 24, Parts 2, 2.5, 3, 4, 5, 6, 7, 9, 10 and 11 shall apply to all occupancies and applications not regulated by a state agency.
1.1.3.2 State-Regulated Buildings, Structures, and Applications. The model code, state amendments to the model code, and/or state amendments where there are no relevant model code provisions shall apply to the fol- lowing buildings, structures, and applications regulated by state agencies as specified in Sections 1.2.0 through 1.14.0, except where modified by local ordinance pur- suant to Section 1.1.8. When adopted by a state agency, the provisions of this code shall be enforced by the appro- priate enforcing agency, but only to the extent of author- ity granted to such agency by the state Legislature.
Note: See “How to Distinguish Between Model Code Language and California Amendments” in the front of the code.
1. State-owned buildings, including buildings con- structed by the Trustees of the California State Uni- versity, and to the extent permitted by California laws, buildings designed and constructed by the Regents of the University of California, and regu-
lated by the Building Standards Commission. See Section 1.2.0 for additional scope provisions.
2. Section 1.3.0 is reserved for the Board of State and Community Corrections.
Frequently asked questions
Who must perform the inspection required by § 503.1?
The inspection is performed by the Authority Having Jurisdiction (the local building department or their inspector) as required by the permit; the inspection must occur after installation and before the vent or chimney is covered or concealed.
Does § 503.1 require periodic inspections after the vent is concealed?
No — § 503.1 requires a pre‑concealment inspection (after installation and before covering). Periodic maintenance/inspections (for example, smoke/heat vents) are governed elsewhere (see Fire Code § 910.5).
Can a contractor cover a vent if they have photos showing the installation?
No. The code requires an on‑site inspection by the Authority Having Jurisdiction before covering; photographic evidence does not replace the required inspection under § 503.1.
Where do I find the technical sizing/clearance requirements for a water‑heater vent?
Those technical requirements appear in the CPC venting chapters and appliance vent sections (e.g., § 509.x and related tables). The file you provided shows § 504.2 exists but did not include the full text; consult the CPC book or your local building department for the full § 504.2 text and the appliance venting sections.
If a smoke/heat vent is installed, does § 503.1 apply?
§ 503.1’s pre‑concealment inspection requirement applies to chimneys and vents installed under a permit. Smoke/heat vents have additional inspection and maintenance requirements set forth in the California Fire Code (e.g., Fire Code § 910.5), which prescribes inspection/test frequencies. Follow both the CPC inspection timing and the Fire Code maintenance schedule as applicable.
More in California Plumbing Code
- Administration
- Definitions
- General Regulations
- Plumbing Fixtures and Fixture Fittings
- Water Heaters
- Water Supply and Distribution
- Sanitary Drainage (Drain, Waste, and Vent)
- Indirect Wastes
- Vents
- Traps and Interceptors
- Storm Drainage
- Fuel Gas Piping
- Health Care Facilities — Medical Gas and Medical Vacuum Systems
- Alternate Water Sources and Nonpotable Rainwater Catchment Systems
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