I hope that upgrade kit fixes the problem. I haven't had trouble w/runaway temps so maybe it will.
I wish I had time to pull that heater out and raise it up on bricks so I can get under there easier. Cleaning that screen out from underneath is damn near impossible.
I am guessing CessPool is not giving Lowes the new part to sell. Instead I get the part / kit for "Free" - as long as I pony up the $18 for overnight shipping. At least that isn't so expensive.