This was after changing the coils and flame sensor. I suspected a temperature sensor, but also got a thermal fuse since that was next door. I also ordered a igniter as the old one had now been stressed a lot. When the package arrived the igniter was not in the box. APP responded quickly and professionally about the missing igniter and sent another right away, super easy to deal with. To conclude I would like to complement the crew on producing clear and explanatory videos on repairs. I would recommend a few more on general diagnostic videos like checking the coils and sensors, this many ohms type of thing.