Leak detector probe used to check for refrigerant leaks in the water box should be placed through an open drain valve once the water is removed

• A. Through an open drain valve
• B. On the top surface of the water box
• C. Inside the purge unit
• D. At the condenser inlet

Answer: (A)

The main idea is to access the water box interior through the proper opening so the leak detector can sample any refrigerant escaping from that area. Placing the probe through an open drain valve after the water is removed gives direct access to the water box, letting the detector pick up leaks around the seals, joints, or components in that space. If you try to probe from the top surface, inside the purge unit, or at the condenser inlet, you’re not sampling the same path or volume where leaks would vent, so you could miss leaks or get false readings. The drain valve provides the correct access point for an effective leak check of the water box.