Performed the level 2 furnace cleaning. CO levels in the exhaust were excessively high. Heat exchanger also failed the draft smoke test. I located a crack in the heat exchanger. Due to this, I shut the unit down for safety reasons. We will be in touch for options with the heat exchanger. I also performed the fireplace cleaning. I wiped away the dust around the unit. Walls are clean. Glass is clean. Pilot is clean. I also rearranged the logs because some were a little out of place. Unit is heating properly.