CPC · California Plumbing Code

How are cooling water, boiler blowoff, condensers and high‑temperature discharges handled as indirect wastes?

Q: Are there material or thickness requirements for condensers or sumps?

Yes. Concrete sumps must have walls and bottom ≥ 4 inches thick and be plastered inside ≥ 1/2 inch ; metal condensers must be at least No. 12 gauge and protected from external corrosion. § 810.2

The California Plumbing Code requires that cooling water and any boiler blowoff or steam/hot‑water discharged under pressure (or above 140°F) be routed to the drainage system only through an approved indirect device (funnel into a trap, open/closed condenser, or intercepting sump). Condensers and sumps have specific trap, venting, sizing, construction and cleaning requirements (see **§ 808.1**, **§ 810.1**, **§ 810.2**, **§ 810.3**).

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Last reviewed: July 6, 2026

What the code requires — 2-4 sentences

The California Plumbing Code requires that certain clear waters used for cooling and any steam or hot‑water blowoff be handled as indirect waste (not directly tied into the drainage system) and routed through approved receptors such as condensers or intercepting sumps. Specifically, § 808.1 governs clean cooling water discharges to indirect receptors, and § 810.1–§ 810.3 set the rules for high‑temperature discharges, condensers/sumps construction and required cleaning/access.

The single most important rule: Do not directly connect steam or water discharged under pressure above 140°F (60°C) to the building drainage — it must go through an approved indirect device (condenser, open sump or intercepting tank). § 810.1

Requirements in detail

Scope & plain‑English meaning

Indirect waste: discharges that must enter the drainage system through an intervening device (air gap, condenser, sump, funnel into a trap inlet, etc.) rather than a direct piping connection.
High‑temperature limit: water > 140°F (60°C) or any steam under pressure cannot be directly connected into the plumbing/drainage system — use an indirect connection. § 810.1
Cooling water that is “clean running water used exclusively as a cooling medium” may be routed into the drainage system by discharging into the inlet side of an approved fixture trap (funnel style) when no suitable fixture exists — but only where allowed by the Authority Having Jurisdiction (AHJ). § 808.1

Key construction and sizing requirements

Use the table below to see the decision‑critical dimensions you must check during design or plan review.

Decision item	Required value / rule	Code Reference
High‑temperature prohibition	No direct connection of steam or water discharged under pressure above 140°F (60°C)	§ 810.1
Allowed indirect receptor for cooling water	Funnel into inlet side of a fixture trap, funnel ≥ 6 inches (152 mm) above fixture overflow rim (when AHJ allows)	§ 808.1
Trap arrangement for closed condensers/sumps	Provide a deep seal trap extended to within 6 inches (152 mm) of the tank bottom; top of the trap must have a 3/4‑inch (19.1 mm) opening at the highest point as a siphon breaker	§ 810.1
Minimum waterline in condenser/sump	Outlet(s) located so the waterline permanently occupies not less than 1/2 the capacity of the condenser/sump	§ 810.1
Pipe connection sizes (blowoff / water outlet / vent)	See Table 810.1 (e.g., 1‑1/2" blowoff → 1‑1/2" outlet → 4" vent)	Table 810.1 / § 810.1
Concrete condenser/sump construction	Concrete walls & bottom ≥ 4 inches (102 mm) thick; interior plaster ≥ 1/2‑inch (12.7 mm)	§ 810.2
Metal condenser construction	Metal condensers ≥ No. 12 U.S. gauge (0.109 in / 2.77 mm); protect external surfaces with approved bituminous coating	§ 810.2
Required cleaning/access & minimum volume	Sumps/condensers must have access for cleaning and have volume ≥ twice the volume of water removed from the connected boiler(s) when the normal boiler water level is reduced 4 inches (102 mm)	§ 810.3

(Full pipe‑size mapping is shown in Table 810.1 — included above in the table column reference. Use Table 810.1 when selecting blowoff/inlet/vent sizes.)

How the indirect connection is installed (typical)

For steam/pressure blowoff: discharge into an open or closed condenser or an intercepting sump that prevents steam or pressurized water from entering the drainage line. Closed condensers/sumps must be vented to roof, full‑size, separately. § 810.1
For clean cooling water (non‑hazardous): when a suitable fixture is not available and with AHJ approval, route a pipe to the inlet side of an approved fixture trap; terminate the upper end in a funnel‑shaped receptacle not less than 6 inches above the overflow rim. § 808.1

Exceptions & special cases

AHJ discretion: The Code repeatedly defers to the Authority Having Jurisdiction (AHJ) or the boiler manufacturer for the exact indirect waste arrangement where indicated (for example, permitted indirect waste piping for boiler discharges). Follow AHJ direction and manufacturer instructions where they conflict or provide more specific guidance. § 810.1
Table 810.1 note: The blowoff‑condenser sizing table is intended for boilers of 100 square feet (9.29 m²) heating surface or less; larger or atypical boilers may require engineering judgment or AHJ approval. Table 810.1 / § 810.1
Condensers receiving steam or hot water under pressure: must pass through an open sump before entering the drainage system (i.e., closed condenser → open sump → drain). § 810.1

Common mistakes

Directly piping a steam blowoff or pressurized hot water (> 140°F (60°C)) into the sanitary drain without an indirect device — this violates § 810.1.
Forgetting to vent a closed condenser/sump separately and full‑size to the roof as required — vents must be taken off the top and extended above the roof. § 810.1
Incorrect trap configuration: failing to provide a deep‑seal trap reaching within 6 inches of the tank bottom or omitting the 3/4‑inch siphon breaker opening. § 810.1
Undersizing condensers/sumps (not meeting the ≥ 2× blowdown volume rule) or omitting access/cleanouts required by § 810.3.
Using unsuitable materials (e.g., thin metal shells for condensers without corrosion protection) contrary to § 810.2.

Worked example — concrete scenario

Scenario: A single boiler, when blown down such that the normal water level is reduced 4 inches, discharges 20 gallons of water. The blowoff connection from that boiler is 1‑1/2 inches.

Sump volume requirement: Sumps/condensers must contain at least twice the volume removed when the water level drops 4 inches. Required sump volume = 2 × 20 gallons = 40 gallons minimum. § 810.3
Pipe sizing (per Table 810.1): For a 1‑1/2" boiler blowoff, Table 810.1 requires a 1‑1/2" water outlet and a 4" vent. Select fittings and piping to match these sizes and ensure the vent is run full size to the roof and taken off the top of a closed condenser if used. Table 810.1 / § 810.1
Trap & siphon breaker: If using a closed condenser or sump, provide a deep seal trap that reaches within 6 inches of the tank bottom and include the 3/4‑inch opening at the highest point of the trap to serve as the siphon breaker. § 810.1
Material & construction: If the sump is concrete, make the walls and bottom ≥ 4 inches thick and plaster the interior ≥ 1/2 inch. If metal, use at least No. 12 gauge and protect external corrosion. § 810.2

Verify the AHJ will accept the chosen indirect device and follow boiler manufacturer recommendations where provided. § 810.1

Related provisions

§ 808.1 — Cooling water: funnel into trap inlet when approved by AHJ.
§ 810.1 — High‑temperature discharge: prohibition of direct connection and condenser/sump requirements.
§ 810.2 — Sumps, condensers, and intercepting tanks construction and materials.
§ 810.3 — Cleaning: access and minimum volume (≥ twice blowdown).
§ 814.1 — Condensate disposal and indirect waste rules for condensate from air‑conditioning equipment.
§ 812.1 — Clear water wastes: water lifts, expansion tanks, cooling jackets, drip pans, etc., must discharge through an indirect waste.
§ 807.2 — Undiluted condensate waste material limitations (where relevant).

Code references

Grounded in the retrieved California Plumbing Code — click a citation to read the verbatim passage:

CPC § 809.0 High relevance — show source text
809.0 Drinking Fountains.

809.1 General. Drinking fountains shall be permitted to be installed with indirect wastes through an air break.

810.0 Steam and Hot Water Drainage Condensers and Sumps.

810.1 High-Temperature Discharge. No steam pipe shall be directly connected to plumbing or drainage system, nor shall water having a temperature above 140°F (60°C) be discharged under pressure directly into a drainage system. Pipes from boilers shall discharge by means of indirect waste piping as determined by the Authority Having Jurisdiction or the boiler manufacturer’s recommendations. Such pipes shall be permitted to be indirectly connected by discharging into an open or closed condenser or an intercepting sump of an approved type that will prevent the entrance of steam or such water under pressure into the drainage system. Closed condensers or sumps shall be provided with a vent that shall be taken off the top and extended separately, full size above the roof. Condensers and sumps shall be properly trapped at the outlet with a deep seal trap extending to within 6 inches (152 mm) of the bottom of the tank. The top of the deep seal trap shall have a [3] ⁄ 4 of an inch (19.1 mm) opening located at the highest point of the trap to serve as a siphon breaker. Outlets shall be taken off from the side in such a manner as to allow

a waterline to be maintained that will permanently occupy not

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INDIRECT WASTES

less than one-half the capacity of the condenser or sump. Inlets shall enter above the waterline. Wearing plates or baffles shall be installed in the tank to protect the shell. The sizes of the blowoff line inlet, the water outlets, and the vent shall be as shown in Table 810.1. The contents of condensers

receiving steam or hot water under pressure shall pass through an open sump before entering the drainage system.

TABLE 810.1

PIPE CONNECTIONS IN BLOWOFF

CONDENSERS AND SUMPS (inches)

BOILER BLOWOFF WATER OUTLET VENT

3⁄4* 3⁄4* 2

1 1 21⁄2

11⁄4 11⁄4 3

11⁄2 11⁄2 4

2 2 5

21⁄2 21⁄2 6

For SI units: 1 inch = 25 mm
- To be used only with boilers of 100 square feet (9.29 m [2] ) of heating surface or less.
CPC § 807.2 High relevance — show source text
807.2 Undiluted Condensate Waste. Where undiluted condensate waste from a fuel-burning condensing appliance is discharged into the drainage system, the material in the drainage system shall be cast-iron, galvanized iron, plastic, or other materials approved for this use.

Exceptions:

(1) Where the above condensate is discharged to an exposed fixture tailpiece and trap, such tailpiece and trap shall be permitted to be a copper alloy.

(2) Materials approved in Section 701.0 shall be permitted to be used where data is provided that the condensate waste is adequately diluted.

807.3 Domestic Dishwashing Machine. No domestic dishwashing machine shall be directly connected to a drainage system or food waste disposer without the use of an approved dishwasher air gap fitting on the discharge side of the dishwashing machine. Listed dishwasher air gap fittings shall be installed with the flood-level (FL) marking at or above the flood level of the sink or drainboard, whichever is higher.

808.0 Cooling Water.

808.1 General. Where permitted by the Authority Having Jurisdiction, clean running water used exclusively as a cooling medium in an appliance, device, or apparatus shall be permitted to discharge into the drainage system through the inlet side of a fixture trap in the event that a suitable fixture is not available to receive such discharge. Such trap connection shall be by means of a pipe connected to the inlet side of an approved fixture trap, the upper end terminating in a funnelshaped receptacle set adjacent, and not less than 6 inches (152 mm) above the overflow rim of the fixture.

809.0 Drinking Fountains.

809.1 General. Drinking fountains shall be permitted to be installed with indirect wastes through an air break.

810.0 Steam and Hot Water Drainage Condensers and Sumps.

810.1 High-Temperature Discharge. No steam pipe shall be directly connected to plumbing or drainage system, nor shall water having a temperature above 140°F (60°C) be discharged under pressure directly into a drainage system. Pipes from boilers shall discharge by means of indirect waste piping as determined by the Authority Having Jurisdiction or the boiler manufacturer’s recommendations. Such pipes shall be permitted to be indirectly connected by discharging into an open or closed condenser or an intercepting sump of an approved type that will prevent the entrance of steam or such water under pressure into the drainage system. Closed condensers or sumps shall be provided with a vent that shall be taken off the top and extended separately, full size above the roof. Condensers and sumps shall be properly trapped at the outlet with a deep seal trap extending to within 6 inches (152 mm) of the bottom of the tank. The top of the deep seal trap shall have a [3] ⁄ 4 of an inch (19.1 mm) opening located at the highest point of the trap to serve as a siphon breaker. Outlets shall be taken off from the side in such a manner as to allow

a waterline to be maintained that will permanently occupy not

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INDIRECT WASTES
CPC § 808.0 High relevance — show source text
808.0 Cooling Water . . . . . . . . . . . . . . . .182

808.1 General . . . . . . . . . . . . . . . . . . . . .182

809.0 Drinking Fountains . . . . . . . . . . . .182

809.1 General . . . . . . . . . . . . . . . . . . . . .182

810.0 Steam and Hot Water Drainage Condensers and Sumps . . . . . . . .182

810.1 High-Temperature Discharge . . . .182

Table 810.1 Pipe Connections in Blowoff Condensers and Sumps . . . . . . . .183

810.2 Sumps, Condensers, and Intercepting Tanks . . . . . . . . . . . .183

810.3 Cleaning . . . . . . . . . . . . . . . . . . . .183

810.4 Strainers . . . . . . . . . . . . . . . . . . . .183

811.0 Chemical Wastes . . . . . . . . . . . . .183

811.1 Pretreatment . . . . . . . . . . . . . . . . .183

811.2 Waste and Vent Pipes . . . . . . . . .183

811.3 Joining Materials . . . . . . . . . . . . . .183

811.4 Access . . . . . . . . . . . . . . . . . . . . .183

811.5 Permanent Record . . . . . . . . . . . .183

811.6 Chemical Vent . . . . . . . . . . . . . . .183

811.7 Discharge . . . . . . . . . . . . . . . . . . .183

811.8 Diluted Chemicals . . . . . . . . . . . . .183

812.0 Clear Water Wastes . . . . . . . . . . .183

812.1 General . . . . . . . . . . . . . . . . . . . . .183

813.0 Swimming Pools . . . . . . . . . . . . . .183

813.1 General . . . . . . . . . . . . . . . . . . . . .183

814.0 Condensate Waste and Control . . .183

814.1 Condensate Disposal . . . . . . . . . .183

814.2 Condensate Control . . . . . . . . . . .184

814.3 Condensate Waste Pipe Material and Sizing . . . . . . . . . . . .184

Table 814.3 Minimum Condensate Pipe Size . . . . . . . . . . . . . . . . . . .184

814.4 Appliance Condensate Drains . . .184

814.5 Point of Discharge . . . . . . . . . . . .184

814.6 Condensate Waste from

Air-Conditioning Coils . . . . . . . . . .185

814.7 Plastic Fittings . . . . . . . . . . . . . . .185

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TABLE OF CONTENTS
CPC § 810.3 High relevance — show source text
810.3 Cleaning. Sumps and condensers shall be provided with suitable means of access for cleaning and shall contain a volume of not less than twice the volume of water removed

from the boiler or boilers connected to it where the normal

water level of such boiler or boilers is reduced not less than 4 inches (102 mm).

810.4 Strainers. An indirect waste interceptor is receiving discharge-containing particles that would clog the receptor drain shall have a readily removable beehive strainer.

811.0 Chemical Wastes.

811.1 Pretreatment. Chemical or liquid industrial wastes that are likely to damage or increase maintenance costs on the sanitary sewer system, detrimentally affect sewage treatment or contaminate surface or subsurface waters shall be pretreated to render them innocuous before discharge into a drainage system. Detailed construction documents of the pretreatment facilities shall be required by the Authority Having Jurisdiction.

Piping conveying industrial, chemical, or process wastes from their point of origin to sewer-connected pretreatment facilities shall be of such material and design as to adequately perform its intended function to the satisfaction of the Authority Having Jurisdiction. Drainage discharge piping from pre

treatment facilities or interceptors shall be in accordance with standard drainage installation procedures.

Copper or copper alloy tube shall not be used for chemical or industrial wastes as defined in this section.

811.2 Waste and Vent Pipes. Each waste pipe receiving or intended to receive the discharge of a fixture into which acid or corrosive chemical is placed, and each vent pipe connected thereto, shall be constructed of chlorinated polyvinyl chloride (CPVC), polypropylene (PP), polyvinylidene fluoride (PVDF), chemical-resistant glass, high-silicon iron pipe, or lead pipe with a wall thickness of not less than [1] ⁄ 8 of an inch (3.2 mm); an approved type of ceramic glazed or unglazed vitrified clay; or other approved corrosion-resistant materials. CPVC pipe and fittings shall comply with ASTM F2618. PP pipe and fittings shall comply with ASTM F1412 or CSA B181.3. PVDF pipe and fittings shall comply with ASTM F1673 or CSA B181.3. Chemical-resistant glass pipe and fittings shall comply with ASTM C1053. High-silicon iron pipe and fittings shall comply with ASTM A861.

811.3 Joining Materials. Joining materials shall be of approved type and quality.

811.4 Access. Where practicable, the piping shall be readily accessible and installed with the maximum of clearance from other services.

811.5 Permanent Record. The owner shall make and keep a permanent record of the location of piping and venting carrying chemical waste.

811.6 Chemical Vent. No chemical vent shall intersect

vents for other services.

811.7 Discharge. Chemical wastes shall be discharged in a manner approved by the Authority Having Jurisdiction.

811.8 Diluted Chemicals. The provisions of this section about materials and methods of construction shall not apply to installations such as photographic or x-ray darkrooms or research or control laboratories where minor amounts of ade quately diluted chemicals are discharged.

812.0 Clear Water Wastes.

812.1 General. Water lifts, expansion tanks, cooling jackets, sprinkler systems, drip or overflow pans, or similar devices that discharge clear wastewater into the building drainage system shall discharge through an indirect waste.

813.0 Swimming Pools.
CPC § 801.7 High relevance — show source text
801.7 Drip or Drainage Outlets . . . . . . . .181

802.0 Approvals . . . . . . . . . . . . . . . . . . .181

802.1 General . . . . . . . . . . . . . . . . . . . . .181

803.0 Indirect Waste Piping . . . . . . . . . .181

803.1 Materials . . . . . . . . . . . . . . . . . . . .181

803.2 Copper and Copper Alloys . . . . . .181

803.3 Pipe Size and Length . . . . . . . . . .181

804.0 Indirect Waste Receptors . . . . . . .182

804.1 Standpipe Receptors . . . . . . . . . .182

805.0 Pressure Drainage Connections . . . . . . . . . . . . . . . . .182

805.1 General . . . . . . . . . . . . . . . . . . . . .182

806.0 Sterile Equipment . . . . . . . . . . . . .182

806.1 General . . . . . . . . . . . . . . . . . . . . .182

807.0 Appliances . . . . . . . . . . . . . . . . . .182

807.1 Non-Classed Apparatus . . . . . . . .182

807.2 Undiluted Condensate Waste . . . .182

807.3 Domestic Dishwashing Machine . . . . . . . . . . . . . . . . . . . .182

808.0 Cooling Water . . . . . . . . . . . . . . . .182

808.1 General . . . . . . . . . . . . . . . . . . . . .182

809.0 Drinking Fountains . . . . . . . . . . . .182

809.1 General . . . . . . . . . . . . . . . . . . . . .182

810.0 Steam and Hot Water Drainage Condensers and Sumps . . . . . . . .182

810.1 High-Temperature Discharge . . . .182

Table 810.1 Pipe Connections in Blowoff Condensers and Sumps . . . . . . . .183

810.2 Sumps, Condensers, and Intercepting Tanks . . . . . . . . . . . .183

810.3 Cleaning . . . . . . . . . . . . . . . . . . . .183

810.4 Strainers . . . . . . . . . . . . . . . . . . . .183

811.0 Chemical Wastes . . . . . . . . . . . . .183

811.1 Pretreatment . . . . . . . . . . . . . . . . .183

811.2 Waste and Vent Pipes . . . . . . . . .183

811.3 Joining Materials . . . . . . . . . . . . . .183

811.4 Access . . . . . . . . . . . . . . . . . . . . .183

811.5 Permanent Record . . . . . . . . . . . .183

811.6 Chemical Vent . . . . . . . . . . . . . . .183
CPC § 810.1. High relevance — show source text
Outlets shall be taken off from the side in such a manner as to allow

a waterline to be maintained that will permanently occupy not

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INDIRECT WASTES

less than one-half the capacity of the condenser or sump. Inlets shall enter above the waterline. Wearing plates or baffles shall be installed in the tank to protect the shell. The sizes of the blowoff line inlet, the water outlets, and the vent shall be as shown in Table 810.1. The contents of condensers

receiving steam or hot water under pressure shall pass through an open sump before entering the drainage system.

TABLE 810.1

PIPE CONNECTIONS IN BLOWOFF

CONDENSERS AND SUMPS (inches)

BOILER BLOWOFF WATER OUTLET VENT

3⁄4* 3⁄4* 2

1 1 21⁄2

11⁄4 11⁄4 3

11⁄2 11⁄2 4

2 2 5

21⁄2 21⁄2 6

For SI units: 1 inch = 25 mm
- To be used only with boilers of 100 square feet (9.29 m [2] ) of heating surface or less.
810.2 Sumps, Condensers, and Intercepting Tanks. Sumps, condensers, or intercepting tanks that are constructed of concrete shall have walls and bottom, not less than 4 inches (102 mm) in thickness, and the inside shall be cement plastered not less than [1] ⁄ 2 of an inch (12.7 mm) in thickness. Condensers constructed of metal shall be not less than No. 12 U.S. standard gauge (0.109 inch) (2.77 mm), and such metal condensers shall be protected from external corrosion by an approved bituminous coating.

810.3 Cleaning. Sumps and condensers shall be provided with suitable means of access for cleaning and shall contain a volume of not less than twice the volume of water removed

from the boiler or boilers connected to it where the normal

water level of such boiler or boilers is reduced not less than 4 inches (102 mm).

810.4 Strainers. An indirect waste interceptor is receiving discharge-containing particles that would clog the receptor drain shall have a readily removable beehive strainer.

811.0 Chemical Wastes.

811.1 Pretreatment. Chemical or liquid industrial wastes that are likely to damage or increase maintenance costs on the sanitary sewer system, detrimentally affect sewage treatment or contaminate surface or subsurface waters shall be pretreated to render them innocuous before discharge into a drainage system. Detailed construction documents of the pretreatment facilities shall be required by the Authority Having Jurisdiction.

Piping conveying industrial, chemical, or process wastes from their point of origin to sewer-connected pretreatment facilities shall be of such material and design as to adequately perform its intended function to the satisfaction of the Authority Having Jurisdiction. Drainage discharge piping from pre

treatment facilities or interceptors shall be in accordance with standard drainage installation procedures.
CPC § 811.3 High relevance — show source text
CPVC pipe and fittings shall comply with ASTM F2618. PP pipe and fittings shall comply with ASTM F1412 or CSA B181.3. PVDF pipe and fittings shall comply with ASTM F1673 or CSA B181.3. Chemical-resistant glass pipe and fittings shall comply with ASTM C1053. High-silicon iron pipe and fittings shall comply with ASTM A861.

811.3 Joining Materials. Joining materials shall be of approved type and quality.

811.4 Access. Where practicable, the piping shall be readily accessible and installed with the maximum of clearance from other services.

811.5 Permanent Record. The owner shall make and keep a permanent record of the location of piping and venting carrying chemical waste.

811.6 Chemical Vent. No chemical vent shall intersect

vents for other services.

811.7 Discharge. Chemical wastes shall be discharged in a manner approved by the Authority Having Jurisdiction.

811.8 Diluted Chemicals. The provisions of this section about materials and methods of construction shall not apply to installations such as photographic or x-ray darkrooms or research or control laboratories where minor amounts of ade quately diluted chemicals are discharged.

812.0 Clear Water Wastes.

812.1 General. Water lifts, expansion tanks, cooling jackets, sprinkler systems, drip or overflow pans, or similar devices that discharge clear wastewater into the building drainage system shall discharge through an indirect waste.

813.0 Swimming Pools.

813.1 General. Pipes carrying wastewater from swimming or wading pools, including pool drainage and backwash from filters, shall be installed as an indirect waste. Where a pump is used to discharge pool waste water to the drainage system, the pump discharge shall be installed as an indirect waste.

814.0 Condensate Waste and Control.

814.1 Condensate Disposal. Condensate from air washers, air-cooling coils, condensing appliances, and the over

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INDIRECT WASTES

flow from evaporative coolers and similar water-supplied equipment or similar air-conditioning equipment shall be collected and discharged to an approved plumbing fixture or disposal area. Where discharged into the drainage system, equipment shall drain using an indirect waste pipe. The waste pipe shall have a slope of not less than [1] ⁄ 8 inch per foot (10.4 mm/m) or 1 percent slope and shall be of an approved corrosion-resistant material not smaller than the outlet size in

accordance with Section 814.3 or Section 814.4 for air-cooling coils or condensing appliances, respectively. Condensate or wastewater shall not drain over a public way.

814.1.1 Condensate Pumps. Where approved by the Authority Having Jurisdiction, condensate pumps shall be installed in accordance with the manufacturer’s instal lation instructions. Pump discharge shall rise vertically to a point where it is possible to connect to a gravity condensate drain and discharged to an approved disposal point. Each condensing unit shall be provided with a separate sump and interlocked with the equipment to prevent the equipment from operating during a failure. Separate pumps shall be permitted to connect to a single gravity indirect waste where equipped with check valves and approved by the Authority Having Jurisdiction.
CPC § 814.0 Medium relevance — show source text
814.0 Condensate Waste and Control.

814.1 Condensate Disposal. Condensate from air washers, air-cooling coils, condensing appliances, and the over

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INDIRECT WASTES

flow from evaporative coolers and similar water-supplied equipment or similar air-conditioning equipment shall be collected and discharged to an approved plumbing fixture or disposal area. Where discharged into the drainage system, equipment shall drain using an indirect waste pipe. The waste pipe shall have a slope of not less than [1] ⁄ 8 inch per foot (10.4 mm/m) or 1 percent slope and shall be of an approved corrosion-resistant material not smaller than the outlet size in

accordance with Section 814.3 or Section 814.4 for air-cooling coils or condensing appliances, respectively. Condensate or wastewater shall not drain over a public way.

814.1.1 Condensate Pumps. Where approved by the Authority Having Jurisdiction, condensate pumps shall be installed in accordance with the manufacturer’s instal lation instructions. Pump discharge shall rise vertically to a point where it is possible to connect to a gravity condensate drain and discharged to an approved disposal point. Each condensing unit shall be provided with a separate sump and interlocked with the equipment to prevent the equipment from operating during a failure. Separate pumps shall be permitted to connect to a single gravity indirect waste where equipped with check valves and approved by the Authority Having Jurisdiction.

814.2 Condensate Control. Where any equipment or appliance is installed in a space where damage is capable of resulting from condensate overflow, a drain line shall be provided and shall be drained in accordance with Section 814.1.

An additional protection method for condensate overflow shall be provided in accordance with one of the following:

(1) A water level detecting device that will shut off the equipment or appliance in the event the primary drain is blocked. Such detecting device shall be in accordance with the manufacturer’s installation instructions.

(2) An additional watertight pan of corrosion-resistant material, with a separate drain line, installed beneath the cooling coil, unit, or the appliance to catch the overflow condensate due to a clogged primary condensate drain.

(3) An additional separate drain line at a level that is higher than the primary drain line connection of the drain pan.

(4) An additional watertight pan of corrosion-resistant material with a water level detection device installed beneath

the cooling coil, unit, or the appliance to catch the overflow condensate due to a clogged primary condensate drain and to shut off the equipment.

The additional pan or the additional drain line connection shall be provided with a drainpipe of not less than [3] ⁄ 4 of an inch (20 mm) nominal pipe size, discharging at a point that is readily observed.

814.2.1 Protection of Appurtenances. Where insulation or appurtenances are installed where damage is capable of resulting from a condensate drain pan overfill, such installations shall occur above the rim of the drain

pan with supports. Where the supports are in contact with the condensate waste, the supports shall be of approved corrosion-resistant material.
CPC § 316.0 Medium relevance — show source text
INCREASERS AND REDUCERS . . . . . . . . . . . . . . . .316.0

INDIRECT-FIRED WATER HEATERS . . . . . . . .211.0, 505.4,

603.5.4, 608.7 INDIRECT WASTE . . . . . . . . . . . . . . . . . . . . . . . .Chapter 8 Air gap or break . . . . . . . . . . . . . . . . . . . . . . . . . . .801.2 Appliances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .807.0 Approval required . . . . . . . . . . . . . . . . . . . . . . . . .802.0 Aspirators . . . . . . . . . . . . . . . . . . . . . . .603.5.9, 1303.5

Chemical wastes . . . . . . . . . . . . . . . . . . . . . . . . . .811.0

Cleanouts . . . . . . . . . . . . . . . . . . . . . . . . .801.3.2, 803.3

Clear water wastes . . . . . . . . . . . . . . . . . . . . . . . .812.0

Condensate . . . . . . . . . . . . . . . . . .814.1, 814.1.1, 814.5 Food handling fixtures . . . . . . . . . . . . . . . . . . . . .801.3.3 High temperature discharge . . . . . . . . . . . . . . . . .810.1 Interceptor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .902.1 Receptors . . . . . . . . . . . . . . . . . . . . . . . . . .801.4, 804.0 Sterile equipment . . . . . . . . . . . .801.6, 806.0, 1303.4.1 Swimming pools . . . . . . . . . . . . . . . . . . . . . . . . . .813.0 Traps . . . . . . . . . . . . . . . . . . . . . . .801.3.2, 803.3, 814.5

Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .803.3

Where required . . . . . . . . . . . . . . . . . . . . . . . . . . .801.2

INDIVIDUAL VENTS . . . . . . . . . . .211.0, Table 703.2, 904.1,

908.2.1

2025 CALIFORNIA PLUMBING CODE 569

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

INDEX

INDUSTRIAL WASTES
CPC § 309.0 Medium relevance — show source text
309.0 Workmanship.

309.1 Engineering Practices. Design, construction, and workmanship shall comply with accepted engineering practices and shall be of such character as to secure the results sought to be obtained by this code.

309.2 Concealing Imperfections. It shall be unlawful to conceal cracks, holes, or other imperfections in materials by welding, brazing, or soldering, by using therein or thereon paint, wax, tar, solvent cement, other leak-sealing or repair agent.

309.3 Installation Practices. Mechanical systems shall be installed in a manner that is in accordance with this code, applicable standards, and the manufacturer’s installation instructions. All mechanical systems shall be in accordance with construction documents approved by the Authority Having Jurisdiction.

310.0 Condensate Wastes and Control.

310.1 Condensate Disposal. Condensate from air washers, air-cooling coils, condensing appliances, and the overflow from evaporative coolers and similar water-supplied equipment or similar air-conditioning equipment shall be collected and discharged to an approved plumbing fixture or disposal area. Where discharged into the drainage system, equipment shall drain by means of an indirect waste pipe. The waste pipe shall have a slope of not less than [1] ⁄ 8 inch per foot (10.4 mm/m) or 1 percent slope and shall be of approved corrosion-resistant material not smaller than the outlet size in

accordance with Section 310.3 or Section 310.4 for air-cooling coils or condensing appliances, respectively. Condensate or wastewater shall not drain over a public way.

310.1.1 Condensate Pumps. Where approved by the Authority Having Jurisdiction, condensate pumps shall be installed in accordance with the manufacturer’s installation instructions. Pump discharge shall rise vertically to a point where it is possible to connect to a gravity condensate drain and discharged to an approved disposal point. Each condensing unit shall be provided with a separate sump and interlocked with the equipment to prevent the equipment from operating during a failure. Separate pumps shall be permitted to connect to a single gravity indirect waste where equipped with check valves and approved by the Authority Having Jurisdiction.

310.2 Condensate Control. Where any equipment or appliance is installed in a space where damage is capable of resulting from condensate overflow, a drain line shall be provided and shall be drained in accordance with Section 310.1. An additional protection method for condensate overflow shall be provided in accordance with one of the following:

(1) A water level detecting device that will shut off the equipment or appliance in the event the primary drain is

EQUIPMENT CAPACITY IN
TONS OF REFRIGERATION MINIMUM CONDENSATE
PIPE DIAMETER
(inches)

Up to 20 3⁄4

21 – 40 1

41 – 90 11⁄4

91 – 125 11⁄2

126 – 250 2

For SI units: 1 ton of refrigeration = 3.52 kW, 1 inch = 25 mm
CPC § 110.2 Medium relevance — show source text
Compliance with the cooling-only perfor-
mance is required as defined in Notes b and c of Table 110.2-I.
f. For liquid source heat recovery chilling packages that have capabilities for heat rejection to a heat recovery condenser and a tower condenser, the COPHR applies to operation
at full load with 100 percent heat recovery (no tower rejection). Units that only have capabilities for partial heat recovery shall meet the requirements of Table 110.2-D, Water
Chilling Packages—Minimum Efficiency Requirements.
g. For heat recovery heating chilling package applications where there is simultaneous cooling and heating, compliance with the heating performance heat recover COPHR is
only required at one of the four heating AHRI 550/590 (I-P) standard ratings conditions of Low, Medium, Hot-Water 1 or Hot-Water 2. Compliance with the cooling-only perfor-
mance is required as defined in Notes b and c of Table 110.2-I.
h. Water-to-water heat pumps with a capacity less than 135,000 Btu/h are included in Table 110.2-B, Heat Pumps—Minimum Efficiency Requirements.
i. Source leaving liquid temperature.
1. The cooling evaporator liquid flow rate used for the heating rating for a reverse cycle air-to-water heat pump shall be the flow rate determined during the full-load cool-
ing rating.
2. The cooling evaporator liquid flow rate for the simultaneous cooling and heating and heat recovery liquid cooled chilling packages rating shall be the liquid flow rates
from the cooling operation full-load rating.
3. For heating-only fluid-to-fluid chiller packages, the evaporator flow rate obtained with an entering liquid temperature of 54°F and a leaving liquid temperature of 44°F
shall be used.
j. NA means the requirements are not applicable.|a. The size category is the full-load net refrigeration cooling mode capacity, which is the capacity of the evaporator available for cooling of the thermal load external to the chill-
ing package.
b. For air source heat pumps, compliance with both the 47°F and 17°F heating source outdoor air temperature (OAT) rating efficiency is required for heating.
c. Heating full-load rating conditions are at standard rating conditions defined in AHRI 550/590 (I-P), Table 4, which includes the impact of defrost for air source heating ratings.
d. For units that operate in both cooling and heating, compliance with both the cooling and heating efficiency is required.
e. For heat recovery heating chilling package applications where there is simultaneous cooling and heating, compliance with the heating performance heat recover COPHR is
only required at one of the four heating AHRI 550/590 (I-P) standard ratings conditions of Low, Medium, Hot-Water 1 or Hot-Water 2. Compliance with the cooling-only perfor-
mance is required as defined in Notes b and c of Table 110.2-I.
f. For liquid source heat recovery chilling packages that have capabilities for heat rejection to a heat recovery condenser and a tower condenser, the COPHR applies to operation
at full load with 100 percent heat recovery (no tower rejection). Units that only have capabilities for partial heat recovery shall meet the requirements of Table 110.2-D, Water
Chilling Packages—Minimum Efficiency Requirements.
g.
CPC § 302.6 Medium relevance — show source text
Protection from damage . . . . . . . . . . . . . . . . . . .E 302.6 Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .603.2 BACKFLOW PREVENTION . . . . . . . . . . . . . . .602.3, 603.3

BACK-TO-BACK FIXTURES . . . . . . . . . . . . . . . . . . . .704.2

BACKWATER VALVES

Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204.0

Where Required. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 710.6 BALLCOCKS . . . . . . . . . . . . . . . . . . . .Table 603.2, 603.5.2

BAPTISTRIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .406.1

BATHROOM, HALF, DEFINITION . . . . . . . . . . . . . . . .204.0

BATHROOM GROUP . . . . . . . . . . . . .204.0, 908.2, C 303.0

BATHTUB, PROHIBITED TYPE . . . . . . . . . . . . . . . . .405.3

BATHTUBS AND

WHIRLPOOL BATHTUBS . . . . . . . . . . . . . . . . . . . .409.0

BIDETS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .402.5, 410.0

BLOWOFF CONDENSERS . . . . . . . . . . .810.1, Table 810.1

BOARD OF APPEALS . . . . . . . . . . . . . . . . . . . . . . . . .107.0

BODY SPRAY, DEFINITION . . . . . . . . . . . . . . . . . . . .204.0

BOILER BLOWOFF

Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .204.0

Discharge requirements . . . . . . . . . . . . . . . . . . . .810.1

BONDING JUMPER

Bonding of CSST fuel gas piping . . . . . . . . . . . . .1211.2

Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .204.0

BOTTLING ESTABLISHMENTS . . . . . . . . . . . . . . . .1013.0

BUILDING DRAIN

Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .204.0

BOILER BLOWOFF	WATER OUTLET	VENT
3⁄4*	3⁄4*	2
1	1	21⁄2
11⁄4	11⁄4	3
11⁄2	11⁄2	4
2	2	5
21⁄2	21⁄2	6

BOILER BLOWOFF	WATER OUTLET	VENT
3⁄4*	3⁄4*	2
1	1	21⁄2
11⁄4	11⁄4	3
11⁄2	11⁄2	4
2	2	5
21⁄2	21⁄2	6

EQUIPMENT CAPACITY IN TONS OF REFRIGERATION	MINIMUM CONDENSATE PIPE DIAMETER (inches)
Up to 20	3⁄4
21 – 40	1
41 – 90	11⁄4
91 – 125	11⁄2
126 – 250	2

Frequently asked questions

Can I pipe a boiler pressure‑relief or blowoff directly to a drain if the water cools before it reaches the drain?

No. Any steam pipe or water discharged under pressure at temperatures above 140°F (60°C) may not be directly connected to the drainage system; you must use an approved indirect arrangement such as discharging into a condenser or intercepting sump per § 810.1.

When is it acceptable to discharge cooling water into a sink trap inlet?

Clean running water used only as a cooling medium may be discharged into the inlet side of a fixture trap via a funnel‑type receptacle at least 6 inches above the fixture overflow rim — but only where the AHJ permits this arrangement. § 808.1

How big must a condenser/sump be for boiler blowoff?

Sumps/condensers must have access for cleaning and contain at least twice the volume of water removed from the connected boiler(s) where the normal boiler water level is reduced 4 inches. § 810.3

Does a closed condenser need a vent?

Yes. Closed condensers or sumps require a vent taken off the top and extended separately, full size, above the roof. § 810.1

Are there material or thickness requirements for condensers or sumps?

Yes. Concrete sumps must have walls and bottom ≥ 4 inches thick and be plastered inside ≥ 1/2 inch; metal condensers must be at least No. 12 gauge and protected from external corrosion. § 810.2

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Related in the CPC

What are the pretreatment, materials and venting requirements for chemical/industrial indirect wastes?

How must condensate be disposed of and what are the rules for condensate pumps?

What appliance discharges require air gaps (dishwashers, sterilizers, drinking fountains)?

Special indirect wastes: chemical, condensate, cooling, steam, pools and appliances

California Plumbing Code