Which of the following is not a symptom of a refrigerant leak?

High discharge pressure is not typically associated with a refrigerant leak. In fact, a refrigerant leak generally results in a lower refrigerant charge within the system, leading to reduced cooling efficiency and performance. When there is insufficient refrigerant, the system struggles to maintain the proper pressures required for effective operation. As a result, discharge pressure usually tends to be lower when there is a leak, as there is not enough refrigerant to absorb and move heat effectively through the system.

On the other hand, reduced cooling performance is a direct result of a refrigerant leak, as the system cannot adequately cool air without sufficient refrigerant. Bubbles in the sight glass indicate that there's a low refrigerant level, showcasing another symptom of a leak. Frost on the evaporator coil can also occur due to low refrigerant levels resulting from a leak, as the coil may become too cold and freeze moisture when insufficient refrigerant is present to absorb heat efficiently. Thus, understanding these symptoms can help HVAC technicians diagnose refrigerant leaks effectively.