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Is a PVC condensate drain up to code in San José?

Usually yes for a small drain. The California Mechanical Code and Plumbing Code allow PVC for condensate waste piping smaller than 1-1/4 inch.23 The code also sets slope, cleanouts, overflow protection and where the drain can end.1

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The short version

Pipe under 1-1/4 inch: PVC allowed

Condensate waste piping smaller than 1-1/4 inch can be PVC, CPVC, PE, PP, copper or another rigid material the authority approves.2

1-1/4 inch and larger: plumbing code materials

Air-conditioning waste pipes of 1-1/4 inch and larger use the materials listed in the plumbing code.23

Where it ends matters as much

The drain ends with an air gap or air break at an approved place, never over a public way.14

What the code asks of a condensate drain

San José adopts the 2025 California Mechanical and Plumbing Codes.6 The City page adds its own termination list.1

  1. Pick the material

    PVC is fine for lines under 1-1/4 inch. The material also has to suit the pressure and temperature rating of the equipment and be approved for the liquid being discharged.2

  2. Size the line

    For air-cooling coils, the minimum is 3/4 inch up to 20 tons of refrigeration, 1 inch for 21 to 40 tons, 1-1/4 inch for 41 to 90 tons, 1-1/2 inch for 91 to 125 tons and 2 inch for 126 to 250 tons.2 Drains from single condensing appliances follow the maker's instructions.

  3. Set the slope and corrosion rating

    At least 1/8 inch per foot (1 percent), in approved corrosion-resistant material, no smaller than the equipment outlet.4

  4. Add a cleanout

    The line must be configured or provided with a cleanout so a blockage can be cleared without cutting the drain.2

  5. Protect against overflow

    Where a spill could do damage, add a float switch, a second pan with its own drain, or a second drain line.4

  6. End it at an approved point

    Use an air gap or air break to a trapped, vented receptacle, a dry well, a fixture tailpiece or a bioswale.1 Then schedule the inspection. See our inspection guide.

City termination and drywell rules

Drywell, option 1
At least 2 feet square and 2 feet deep, at least 3 feet from the foundation, filled with 1 inch rock or gravel, covered with building paper or plastic and 6 inches of earth or concrete. A condensate pipe of at least 3/4 inch connects indirectly to a drainpipe of at least 1-1/2 inch, by an air gap or air break at the edge of the foundation.1
Drywell, option 2
24 inch grade rings, at least two rings for up to 30 tons, at least 8 feet from the foundation, with a solid concrete cover and a 6 inch layer of 1 inch rock around the bottom and sides.1
Equipment in an attic
The City refers to the secondary protection rules in CMC 310.2 and CPC 814.2 for equipment in an attic, furred space or dropped ceiling.1
Always check the current code
The City says to check the current Building, Plumbing and Mechanical codes and the manufacturer's installation instructions. Your inspector decides what is approved for your job.1

Replacing an AC or water heater? We handle the permit and the drain.

Tell us about the equipment and where the drain runs now. We pull the permit, build the drain to code and schedule the inspection through final.

  • The city and the age of the house
  • The equipment: AC, furnace, heat pump or water heater
  • Where the unit sits and where the drain ends now

Prefer to talk? Call (408) 667-4946 or send a text. Office hours: Monday to Friday, 7 am to 3 pm.

David and Tristan, the owners, stay involved from the first walkthrough to the final check. We reply the same business day, Monday to Friday.

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Condensate drains: common questions
Is PVC allowed for an AC condensate drain in San Jose?
Generally yes for small drains. The California Mechanical Code and Plumbing Code say condensate waste piping smaller than 1-1/4 inch is permitted to be PVC, CPVC, PE, PP, copper or other rigid materials approved by the authority having jurisdiction. Pipe 1-1/4 inch and larger must be made of the materials listed in the plumbing code.
What size does the condensate drain need to be?
For air-cooling coils, the code sets a minimum pipe size by capacity: 3/4 inch up to 20 tons of refrigeration, 1 inch for 21 to 40 tons, and larger above that. Drains from individual condensing appliances are sized as the manufacturer requires.
What slope does a condensate drain need?
At least 1/8 inch per foot, which is 1 percent. The drain must also be of approved corrosion-resistant material and has to be configured with a cleanout, or be provided with one, so a blockage can be cleared without cutting the line.
Where can the condensate drain end in San Jose?
The City says an air gap or air break to a trapped, vented receptacle such as a standpipe, mop sink or floor sink, a dry well, the tailpiece of a plumbing fixture, or a bioswale designed for the load. For single-family and duplex properties a heat pump water heater can end at an exterior surface that is not part of a main entrance or egress path, with a splash block at landscape terminations. Condensate cannot drain over a public way.
Do I need a second drain or overflow switch?
If the equipment sits where a condensate overflow could cause damage, such as an attic, the code requires a secondary method: a water level device that shuts off the equipment, a second watertight pan with its own drain, a second drain line set higher than the primary connection, or a pan with a level device. The extra pan or drain line is at least 3/4 inch and ends where it is easy to see.

Sources

This page explains published code and City rules for condensate drains. The City and your inspector decide what applies to your job. Check the City page and the current codes.