What does the primary control do? What will be an ideal ...

[kodithompson]

What does the primary control do?
 
  What will be an ideal response?

Question 2

How does a cad cell sense the flames?
 
  What will be an ideal response?

[batool]

Answer to Question 1

The primary control operates the burner motor and ignition transformer and provides flame safety. On a call for heat, the primary control starts the burner motor and ignition transformer. If flames are not established, the primary control shuts down the oil burner motor and ignition transformer.

Answer to Question 2

By the light. The cad cell resistance is high when it is dark and drops when exposed to light.