I know it doesn't have to glow to be working, but why does it glow sometimes and not others? I would say mine glows very ittermittently. I have noticed no real trend in temps or anything. For instance, I just threw a few splits on, charred them, and then closed the bypass and backed the stat down. The cat probe went from just over the active line to about 1:00 pretty quick and it's holding there but with no glow. Other times the glow is so bright it's visible across the room! Does it have to do with fuel load?
BTW, I just cleaned it and replaced the cat gasket.
BTW, I just cleaned it and replaced the cat gasket.