Which of the following are common leak locations?

• A. Coils
• B. Valve connections
• C. Pipe connections
• D. Coils, valve connections, pipe connections

Answer: (D)

Leaks in HVAC and refrigeration systems tend to show up at joints and connections where refrigerant passages come together. Coils are a common place because they have many brazed joints and connections between tubing and fins, plus potential weak spots at where the coil interfaces with other components. Valve connections can leak if seals like O-rings or gaskets degrade or fittings loosen under pressure. Pipe connections—threaded, flare, or brazed joints—are also frequent leak points due to vibration, thermal cycling, and stress from pressure changes. Since any of these areas can become a leak, the option that includes all three—coils, valve connections, and pipe connections—best reflects where leaks commonly occur. In practice, technicians inspect all of these areas during leak checks to catch leaks wherever they may be hiding.