# Vacuum Breakers: Building Code Definition

> How the IRC 2009 define vacuum breakers, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/vacuum-breakers/
- Last updated: 2026-09-07
- Data source: Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.

## Key facts

| Fact | Value |
| --- | --- |
| Defined in | IRC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IRC 2009 Definitions (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 5 (counted across the codes hosted here) |
| Wording identical across codes | Single code (compare before citing one code's wording under another) |

## Direct answer

Vacuum breakers is a defined term in the International Residential Code (IRC) 2009, in Definitions. The code's own words are: “A device which prevents back-siphonage of water by admitting atmospheric pressure through ports to the discharge side of the device.” No other I-Code in this corpus defines it, so the IRC 2009 definition is the one to work from. The term is used in 5 chapters of this corpus, most often in Water Supply and Distribution (IPC 2009), Water Supply and Distribution (IRC 2009), Fixtures, Faucets and Fixture Fittings (IPC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted. Record the jurisdiction, the adopted edition, the application date and any local amendment that rewrites the definition before you use it on a live project, because a term redefined by amendment changes every requirement that depends on it.

*Content and cited inputs reviewed by [Scott Barrington](https://nz.linkedin.com/in/barrington), Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.*

## What does this term mean?

**Vacuum Breakers** — IRC 2009, Definitions:

> A device which prevents back-siphonage of water by admitting atmospheric pressure through ports to the discharge side of the device.

![Labeled code-term definition diagram: Vacuum Breakers: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/vacuum-breakers/diagram-1344.webp)

*How the IRC 2009 define vacuum breakers, where the wording differs, and which chapters depend on the term.*

## What must be verified before using this guidance?

**Vacuum Breakers** is defined once in this corpus, in the [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) chapter of the International Residential Code (IRC) 2009:

> A device which prevents back-siphonage of water by admitting atmospheric pressure through ports to the discharge side of the device.

## Where vacuum breakers is used in the code

The term appears in 5 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Water Supply and Distribution](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/water-supply-and-distribution.md) | IPC 2009 | 38 |
| [Water Supply and Distribution](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/water-supply-and-distribution.md) | IRC 2009 | 20 |
| [Fixtures, Faucets and Fixture Fittings](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/fixtures-faucets-and-fixture-fittings.md) | IPC 2009 | 3 |
| [General Regulations](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/general-regulations.md) | IPC 2009 | 2 |
| [Definitions](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/definitions.md) | IRC 2009 | 1 |

### The term in use

How the code actually writes about vacuum breakers, quoted from the 2009 text hosted here:

> Vacuum breakers for bedpan washer hoses shall not be located less than 5 feet (1524 mm) above the floor.

— [IPC 2009 §608.3.1](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/water-supply-and-distribution.md)

> Pipe-applied atmospheric-type vacuum breakers shall conform to ASSE 1001 or CSA B64.1.1.

— [IRC 2009 §P2902.3.2](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/water-supply-and-distribution.md)

> Access shall be provided to concealed piping in connection with special fixtures where such piping contains steam traps, valves, relief valves, check valves, vacuum breakers or other similar items that require periodic inspection, servicing, maintenance or repair.

— [IPC 2009 §422.5](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/fixtures-faucets-and-fixture-fittings.md)

> Reduced pressure principle backflow preventer assemblies, double check-valve assemblies, pressure vacuum breaker assemblies, reduced pressure detector fire protection backflow prevention assemblies, double check detector fire protection backflow prevention assemblies' hose connection backflow preventers, and spillproof vacuum breakers shall be tested at the time of installation, immediately after repairs or relocation and at least annually.

— [IPC 2009 §312.10.2](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/general-regulations.md)


## Vacuum Breakers compared with Vacuum Breaker

These two are the closest pair in the 2009 I-Codes: about 52 per cent of their defining words are the same. The code states both and compares neither, so the difference is worth naming.

| | Wording unique to it |
| --- | --- |
| **Vacuum Breakers** (IRC 2009) | back, siphonage, water |
| [Vacuum Breaker](https://harth.build/resources/glossary/vacuum-breaker.md) (IPC 2009) | type, backflow, preventer, installed, openings, subject, normal |

Everything else in the two definitions is shared. If a project turns on which of the two applies, those words are the whole of the test — and a local amendment that edits one of them without editing the other moves the boundary between vacuum breakers and vacuum breaker.

## The terms vacuum breakers is built out of

The definition above leans on 2 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what vacuum breakers covers:

- **[Atmospheric Pressure](https://harth.build/resources/glossary/atmospheric-pressure.md)** — IRC 2009: The pressure of the weight of air and water vapor on the surface of the earth, approximately 14.7 pounds per square inch (psia) (101 kPa absolute) at sea level.
- **[Device](https://harth.build/resources/glossary/device.md)** — IRC 2009: Aunit of an electrical system that carries or controls electrical energy as it principal function.

## Vacuum Breakers: what to open, and in what order

Every row is a document this term depends on. The [ICC code library](https://codes.iccsafe.org/codes) and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) cover the middle rows.

| Check | Where | Confirmed |
| --- | --- | --- |
| Read the definition in the adopted IRC | Definitions | |
| Re-check the requirement that uses it | Water Supply and Distribution (IPC 2009) | |
| Re-check the requirement that uses it | Water Supply and Distribution (IRC 2009) | |
| Re-check the requirement that uses it | Fixtures, Faucets and Fixture Fittings (IPC 2009) | |
| Re-check the requirement that uses it | General Regulations (IPC 2009) | |
| Confirm the dependent definition | Atmospheric Pressure | |
| Confirm the dependent definition | Device | |
| Local amendment to any of the above | Jurisdiction's amendment list | |

**A research aid, not a code determination.** The authority having jurisdiction decides which edition and which amendments apply.

## Where can you explore related guidance?

- [Explore all glossary guidance](https://harth.build/resources/glossary.md)
- [Atmospheric Pressure: Building Code Definition](https://harth.build/resources/glossary/atmospheric-pressure.md)
- [Device: Building Code Definition](https://harth.build/resources/glossary/device.md)

## Sources and method

Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.

### Source links

- [codes.iccsafe.org](https://codes.iccsafe.org/codes)

- [iccsafe.org](https://www.iccsafe.org/advocacy/code-adoption-maps/)

## Frequently asked questions

### What is the code definition of vacuum breakers?

The International Residential Code (IRC) 2009 defines it in Definitions as: “A device which prevents back-siphonage of water by admitting atmospheric pressure through ports to the discharge side of the device.” The 2009 model text is reproduced here; the definition that binds your project is the one in the edition your jurisdiction has adopted, as amended locally.

### Which parts of the code depend on vacuum breakers?

In this corpus the term is used across 5 chapters, led by Water Supply and Distribution in the IPC 2009. Those are the sections whose scope moves if the definition is amended locally, so read them together with Chapter 2 rather than on their own.

### What is a vacuum circuit breaker?

Circuit Breaker is a separate defined term. The IRC 2009 defines it as: “A device designed to open and close a circuit by nonautomatic means and to open the circuit automatically on a predetermined overcurrent without damage to itself when properly applied within its rating.” That is not the same as vacuum breakers, which the IRC 2009 defines as “A device which prevents back-siphonage of water by admitting atmospheric pressure through ports to the discharge side of the device.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

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