https://bbs.wenxuecity.com/fdcj/1878970.html
Changed gas valve and it has worked close to 2 wks now.
intermittent HVAC problem is annoying. When no time pressure to get it fixed, it is like playing puzzle game.
I read more intermittent HVAC problems on reddit. One got my attention. A screw is not tightened
good enough at AC contact and caused tough intermittent HVAC problem. An extra 0.5 ohm resistance could cause quite a bit heating at 40A (or 30A) I^2R and it could oxide the surface and increase the resistance.
Here is one puzzle. Not my posting.
