What is the critical criteria for the installation of a running trap?

The key criterion for the installation of a running trap is that it must have access for cleaning. This is essential because running traps can accumulate debris and other materials over time, which can lead to blockages and affect their functionality. Accessible cleaning points ensure that any buildup can be easily managed, maintaining the efficiency of the plumbing system and preventing backups.

Other considerations, such as having a cleanout on the outlet side, while important, do not capture the necessity for ongoing maintenance access as directly as the need for cleaning access does. Similarly, being at the same height as the inlet may not be critical in all installations, and insulation from temperature changes, while relevant in some contexts, does not pertain specifically to the functioning or maintenance of a running trap. Thus, access for cleaning is the most critical aspect to ensure long-term reliability and effectiveness of the system.