Hi all, new here! I have a question I am hoping someone can answer for me. I recently had my expansion valve replaced in my Rheem rhkl unit. How do I know if the tech overheated my valve? I know he used a wet rag, but I saw slight scorch marks on the valve, and am worried about the valve failing again. I also noticed my valve hissing for short periods of time when the unit is running...louder than the old factory one. Any input would be appreciated. Thank you.