What problem may arise if a proper trap is not used on the condensate drain for a pull-through unit?

Using a proper trap on the condensate drain for a pull-through unit is essential for maintaining proper water flow and pressure within the system. If a proper trap is not utilized, it can lead to issues where condensate does not drain correctly. This occurs because the trap creates a barrier that maintains the necessary water seal, preventing backflow and allowing for the gravity drainage of condensate. Without this trap, the system might experience air pockets or back pressure that can hinder the flow, leading to improper drainage.

Inadequate drainage can result in water accumulation within the unit, potentially causing damage or creating an environment conducive to mold growth, which can affect indoor air quality. Therefore, maintaining a proper trap is crucial to ensure a consistent and effective drainage process in heat pump systems.