Just got done doing a deep clean on my newer model 52i. Took compass and side heat exchangers out along with the flame guide and brushed them clean. Brushed and vacuumed out the entire unit and brushed the fan blades. Here comes the stupid question...where is my ESP located? I put a flash light up the hole near the fan and I don't see anything. Is it back there past where I can see or am I looking in the wrong place?