Updated 2026-09-07

Building Code Glossary

Temperature-relief Valve: Building Code Definition

How the IRC 2009 define temperature-relief valve, where the wording differs, and which chapters depend on the term.

On this page

Last updated September 7, 2026 · 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.

Direct answer

Temperature-relief valve is a defined term in the International Residential Code (IRC) 2009, in Definitions. The code's own words are: “A temperature-actuated valve designed to discharge automatically at the temperature at which it is set.” 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 4 chapters of this corpus, most often in Water Heaters (IRC 2009), Solar Systems (IRC 2009), Boilers and Water Heaters (IRC 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, Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.

What does this term mean?

Temperature-relief Valve — IRC 2009, Definitions:

A temperature-actuated valve designed to discharge automatically at the temperature at which it is set.

Labeled code-term definition diagram: Temperature-relief Valve: Building Code Definition
How the IRC 2009 define temperature-relief valve, where the wording differs, and which chapters depend on the term.

What must be verified before using this guidance?

Temperature-relief Valve is defined once in this corpus, in the Definitions chapter of the International Residential Code (IRC) 2009:

A temperature-actuated valve designed to discharge automatically at the temperature at which it is set.

Where temperature-relief valve is used in the code

The term appears in 4 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

ChapterCodeMentions
Water HeatersIRC 20095
Solar SystemsIRC 20092
Boilers and Water HeatersIRC 20091
DefinitionsIRC 20091

Temperature-relief Valve compared with Pressure-relief Valve

These two are the closest pair in the 2009 I-Codes: about 50 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
Temperature-relief Valve (IRC 2009)temperature, discharge
Pressure-relief Valve (IRC 2009)pressure, held, closed, spring, means, relieve

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 temperature-relief valve and pressure-relief valve.

The terms temperature-relief valve is built out of

The definition above leans on 1 other defined term. Each carries its own code definition, and a local amendment to any of them changes what temperature-relief valve covers:

  • Valve — IRC 2009: A device used in piping to control the gas supply to any section of a system of piping or to an appliance.

Temperature-relief Valve: what to open, and in what order

Every row is a document this term depends on. The ICC code library and the ICC adoption maps cover the middle rows.

CheckWhereConfirmed
Read the definition in the adopted IRCDefinitions
Re-check the requirement that uses itWater Heaters (IRC 2009)
Re-check the requirement that uses itSolar Systems (IRC 2009)
Re-check the requirement that uses itBoilers and Water Heaters (IRC 2009)
Re-check the requirement that uses itDefinitions (IRC 2009)
Confirm the dependent definitionValve
Local amendment to any of the aboveJurisdiction's amendment list

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

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 publishes the current model text and the ICC adoption maps show which edition a jurisdiction has adopted; those sources control.

Frequently asked questions

What is the code definition of temperature-relief valve?

The International Residential Code (IRC) 2009 defines it in Definitions as: “A temperature-actuated valve designed to discharge automatically at the temperature at which it is set.” 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 temperature-relief valve?

In this corpus the term is used across 4 chapters, led by Water Heaters in the IRC 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.

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