Basics: Ruud furnace circa I have no clue
Condition: System cuts off during cycle.
The system will ignite the pilot, flood the burner with gas and ignite, warm the system up, the blower starts and everything seems to be going well then...
...it shuts off.
At first we thought it might be the stack control reading that it's hotter than it actually was...but it won't turn back on all night.
Only when I blow some air at the pilot do I get the system to kick back on and continue it's cycle.
So, I've read about the flame sensor but frankly after reading a post in one of your forums a bit scared to do it. (Ruud furnace issue on upgrade board and flame sensor