Changes to PA UCC Code: Plumbing Code Changes 2009 vs 2015 IECC/IPC

Change. Whether good, bad, or somewhere in between, we must accept change and constantly adapt in order to move forward, grow and even improve. Changes in the International Plumbing and Energy Conservation Codes are no exception. The Commonwealth of Pennsylvania, except for the City of Philadelphia, adopted the 2015 International Codes the past October, superseding the 2009 international Codes that were previously in place.

In this edition of “Insights” we describe a few noteworthy changes between the 2009 and 2015 International Plumbing and Energy Conservation Codes.


Lead Content in Water Supply Piping
Both the 2009 and 2015 codes specifically require that piping, joints, valves, fittings and faucets contain at most 8% lead. However, the 2015 code now requires these components used to supply water for drinking and cooking to be limited to a weighted average of 0.25% or less. Thus, we recommend that any plumbing system having domestic water outlets that supply water for consumption by either drinking or cooking should comply with the latter throughout the system from water service inlet to the remotest device or fixture.

Hot Water Supply
The thermostat on a water heater is not acceptable as the means for limiting the maximum allowable water temperature to fixtures. In other words, thermostatic mixing valves are now required between the hot water system supply and all end-use fixtures to adequately protect building occupants from accidental scalding.

If the developed the length of hot water supply piping from the farthest plumbing fixture to the hot water source exceeds 50 feet, a recirculation (or heat-traced) piping system is required to maintain tempered piping in the system. The 2009 code allowed up to 100 feet.

Dedicated circulator pumps that circulate water between a water heater and a storage tank must be de-energized within five minutes after the heating cycle is completed. This was not referenced in the 2009 code, allowing these circulator pumps to run indefinitely.

Demand controls for recirculation systems are now required. The control system must energize the pump upon use of the system by either sensing occupancy by users at fixtures or by sensing the flow of hot water to fixtures in the system. The control system must also limit the temperature of the recirculated water entering the cold-water system to 104 degrees Fahrenheit.


Domestic Hot Water Systems
Central water heating systems 1,000 MBH or greater must be at least 90% efficient and pool heaters must now be at least 82% efficient.

Piping insulation thickness must now comply with the same requirements as building space heating and cooling requirements with thickness increasing as pipe sizes increase.

The maximum allowable piping length from the heated water source (water heater or circulated piping system) is limited by volume. Water supply to public lavatories is the most affected, with uncirculated lengths of piping ½” and larger being limited to a range of 6 to 24 inches. In order to practically achieve this requirement, hot water recirculation piping must be extended from the fixture behind the wall and back to the return system.

As with the Plumbing Code, pumped circulation systems are required (gravity recirculation systems are no longer permitted) and circulator pump starts must be based on demand rather than by occupancy alone. In addition to the Plumbing Code requirement for demand control, the Energy Conservation Code requires that circulator pumps be de-energized when temperature limits are satisfied.

This is not an exhaustive list of the recent changes, but we have highlighted a few of the significant ones. The International Code Council publishes summaries of significant changes in the codes as compared to the version that immediately precedes it. A summary of changes in both the 2012 and 2015 codes are available for immediate download at

If you have any questions about interpreting these changes or would like to discuss practical implementation of the latest requirements in your building’s plumbing system, please do not hesitate to contact Robert J. Allen, PE, CPD at or 717-845-7654.