National Center for Construction Education & Research (NCCER) Plumbing Level 1 Practice Exam

The primary drawback of using PVC over CPVC in hot water applications is related to heat resistance. CPVC, or chlorinated polyvinyl chloride, is specifically designed to withstand higher temperatures compared to standard PVC. This makes CPVC suitable for hot water transport, as it maintains its structural integrity and performance even at elevated temperatures that would typically cause PVC to weaken or deform.

In contrast, while PVC can be used for cold water applications and some limited hot water applications, it does not possess the same level of temperature tolerance. Using PVC in hot water systems can lead to failures such as warping, leaking, or even catastrophic failure, which underscores the importance of selecting the appropriate material for specific temperature ranges in plumbing systems. Therefore, the heat resistance of CPVC makes it the preferred choice for hot water applications.