Environmental Protection Agency (EPA) MVAC Certification

What does it indicate if the system pressure rises after reaching the required recovery vacuum?

1. Leak in the system

2. System is fully recovered

3. System has no refrigerant

4. Refrigerant is trapped in the compressor

The correct answer is: Leak in the system

When the system pressure rises after achieving the required recovery vacuum, it typically indicates that there is a leak in the system. This rise in pressure suggests that outside air, and possibly moisture, is entering the system, which can happen if the integrity of the system has been compromised. Such leakage prevents the system from maintaining the low pressure that should be present in a vacuum, indicating there is a problem with the sealing of the system. In contrast, if the system were fully recovered, the pressure would remain stable at the achieved vacuum level. The absence of refrigerant would also not result in increased pressures, as there would be no material to create pressure. Similarly, if refrigerant were trapped in the compressor, this wouldn’t inherently cause a rise in system pressure after achieving a vacuum; it would more likely reflect a different issue regarding the refrigerant's flow or state within the system.