Significant changes to shower control valves to be rated for the installed shower head in the 2021 International Plumbing Code

A modification to Section 412.3 (Shower Control Valves to be Rated for the Installed Shower Head) of the 2021 International Plumbing Code states that lower flow shower heads need to be compatible with the shower control (mixing valve).

The code requires a shower head flow rate be limited to 2.5 gpm. Shower controls (mixing valves) complying with the requirements of the product standards in the code are designed to safety operate at that flow. However, there are many different types of shower heads available in the market that have lower flow rates. These lower flows might not provide enough motive power within a mixing valve to allow for the valve to self-adjust to prevent temperature shock to the user when a supply pressure or temperature change occurs. Not all shower controls (mixing valves) are designed (and tested) to accommodate lower (less than 2.5 gpm) flows.

Read the full significant change.

The 2021 Significant Changes guides are available for the International Building, Fire, Residential, Energy Conservation, Plumbing, Mechanical and Fuel Gas Codes. This valuable series can help any code user save time by zeroing in on the most critical changes in the 2021 International Codes. The Code Council’s technical experts provide summaries, analysis and graphics for these changes making them clear and easy to understand. Each edition provides a comprehensive analysis of significant changes since the 2018 edition, offering key insights into its contents and implications. Each change analysis features the affected code sections and identifies the change with strikethroughs and underlines to show modifications to the existing language. Each change is accompanied by a quick summary, detailed illustrations, and a discussion of its significance, which brings the technical jargon of the code to life in a real-world setting.

Significant Changes to the IPC, IMC, and IFGC, 2021 Edition is available in the ICC Store or through Digital Codes Premium for the International Plumbing Code, International Mechanical Code and International Fuel Gas Code.