starts, then you might have a problem like rollout that one of the other sensors is tripping off
Thanks, Mark. I think I may have some roll-out now that I am more educated on this issue. I didn't know that this wasn't normal until now. It looks like it's been doing this for some time (couple years) now, seeing the roll-out sensor just above the flame tubes has been bypassed by the previous home owner. It only appears to be doing this on the third tube from the left. I have uploaded a video to YouTube and will attach the link here:
formatting link
How dangerous is this? The furnace is in my unfinished basement (concrete walls & floor) on a concrete slab with nothing near it that could catch fire. There is a sheet-metal heat shield between the flames and the gas valve, draft inducer, sensors, etc. so no flames are able to come into direct contact with anything else in the furnace.