What function does a cleanout serve in plumbing?

A cleanout in plumbing serves the important function of allowing access to the drainage system for cleaning and maintenance. This access point is vital to prevent clogs and ensure that the drainage system operates effectively. Over time, debris, grease, and other materials can accumulate within the pipes, leading to blockages. When these blockages occur, a cleanout allows plumbers to easily access the interior of the pipes to remove obstructions, perform inspections, and conduct repairs if necessary. This maintenance helps to uphold the overall efficiency of the plumbing system, avoiding potential backups or more serious plumbing issues.

The other options do not accurately represent the purpose of a cleanout. A decorative feature is not a functional aspect of plumbing systems, and cleanouts are strictly utilitarian. Similarly, while cleanouts can indirectly prevent leaks by ensuring that the system operates smoothly, they do not actually seal or prevent leaks in themselves, nor do they have any role in regulating water temperature.