Completed furnace, maintenance and inspection. I cleaned flame sensor and spark igniter. I checked amp draws and components. I checked for carbon monoxide and ran a camera to check the heat exchanger. I tested furnace and low and high stages. The heat exchanger has some strain and some rust on it. I did not see anything of concern today.Furnace is operating within manufacture specifications at departure. Customer is on my monthly membership so we should not have to renew at this time. When we schedule the AC maintenance, we will need to renew the card associated with the membership and also make sure to bring out the smart AC sensors so we can get those set up