you need to provide some intelligible data on this. What were the combustion analysis numbers and what is the appliance doing or not doing? How did you come to this conclusion? By *rich* what do you mean?
If what I think you’re talking about is true I would also suspect a clogged secondary. I encountered many carriers with clogged secondary’s and the symptoms were always the same, awful smell at exhaust, extremely high ppm on my combustion analyzer.
OK relax, here is some data. Found 4 inch filter very plugged (removed), supply temp. at 100 degrees, return temp. 70 degrees, factory spec is 40-70 delta T. Found gas manifold pressure at 3.5 inch water column. Took CO reading in house and readings were 0. Did not take readings out at exhaust. (Stupid) Did notice pressure tape fitting on gas valve on manifold side connected to combustion fresh air intake.
Just took CO readings and it was off the scale, so i am a commercial HVAC guy, can you give me an idea how hard it is to change out a secondary heat exchanger and time involved?? (Still waiting to hear back from Carrier about warranty details)