My SG makes a very loud metallic clang when it turns on. Is that normal? Sounds like someone slamming a very heavy metal door and it sort of "jumps" in the wall box. One day, it rattled the display module loose, which I reseated. It works fine otherwise. I don't recall hearing it previously but I recently had a new pump installed and it is less noisy than the old one, which may have been masking the startup noise from the SG.