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After carefully checking airflow over the indoor coil and making sure that it’s not dirty, and that there isn’t a clogged filter problem, you turn your attention to the refrigeration system. Since this R-22 unit is equipped with a fixed-bore metering device (multiple capillary tube) you implement the use of the superheat method to check the charge. In order to accomplish your evaluation, you employ the chart shown in Figure 1, and plug in the following temperature readings you obtained.
• Air entering the indoor coil: 68°F
• Air entering the outdoor coil: 90°
With your evaluation tests complete, you proceed to your diagnosis.
Your three-part troubleshooting question:
1. What was the superheat reading supposed to be for this unit?
2. What was the actual superheat of the unit?
3. What is your diagnosis?
Compare your answers with ours by clicking here.
Publication date: 05/04/2009