Arrived at location on 3/2/22 - I pulled burners and found that the flame sensor probe was dirty. Cleaned off and watched unit heat up and cycle off on temp. Will order part to avoid this issue in the future. Returned to location on 3/4/22 - I verified part was correct. I removed ignitor, ignitor wire & wire assy. Watched unit heat up on temp. Unit is working at this time.