Where should a leak detector probe be placed to check for refrigerant leaks in the water box?

The correct placement of a leak detector probe is through an open drain valve. This method is effective because refrigerant leaks often migrate to low points within a system where they can accumulate, and the drain valve provides a direct access point to the interior of the water box where potential leaks can be trapped or concentrated. Checking through this valve allows for the detection of refrigerant that may have leaked into the water box area before it disperses or evaporates.

Other placements, while they may provide some access for detection, do not target the most likely areas where refrigerant leaks would accumulate. For instance, placing the probe inside the compressor housing does not allow gauging leaks in the water box itself. Similarly, checking at the refrigerant inlet addresses a different part of the system where refrigerant is being introduced rather than where a leak might occur. The exterior of the appliance would typically not reveal any refrigerant leaks that have not dissipated into the environment. Therefore, using the open drain valve for leak detection is a targeted and logical approach in identifying refrigerant leaks efficiently.