17FEB2023 Jason B Arrived for fall tune up, spoke with homeowner about the systems performance. We had an issue with the door switch not closing please be careful to secure the door shut. Inspected coil, blower cabinet, motor, and all components at the furnace. Found some rust stops on top of inducer. Pull blower and inspect secondary heat exchanger. Found secondary heat exchanger dirty and in need of cleaning. Found gas pressure high at 3.8 iwc. Cycled system into heating and tested heat rise. Heat rise 65 picked up 25 ppm CO on a 15min run time. Spoke with homeowner and explained I would need to pull the heat exchanger. Remove gas manifold, flue, inducer, and all components infront of the heat exchanger. Pull primary and secondary heat exchanger. Found heat exchanger leaking around folds a long top. Called carrier for availability. Spoke with homeowner about pricing and availability. We decided to go ahead and replace the heat exchanger. Reassembled equipment and cycled heating. Syst