What can happen if a check valve is not properly installed?

When a check valve is not properly installed, several issues can arise, all of which contribute to significant problems in a plumbing or water management system.

Increased energy consumption can occur because if a check valve is malfunctioning, pumps may require more effort to push water through the system, leading to inefficiencies and increased energy use.

Backflow of contaminated water is a critical concern as a check valve is designed to prevent backflow. If it is not properly installed, there's a risk that water from the opposite direction can flow back into the system, potentially introducing contaminants. This is especially harmful in systems where clean water is vital.

Reduced water flow efficiency can result from an improperly functioning valve, which may create blockages or excessive resistance to the water flow. This results in a decrease in the overall effectiveness of the system, compromising service delivery.

Considering these factors, it is clear that all the mentioned consequences can arise due to improper installation of a check valve, making the option encompassing all these issues the most accurate choice.