No Ignition, Check Cad Cell
The cad cell detected some amount of light during the ignition trial, but not enough to enter run mode.
-Check the cad cell positioning and clean the eye.
-Set the display to show the cad cell resistance.
-Shield the cad cell from light.
If the display shows is less than 20,000 ohms, unplug the cad cell,
if the display does not read 999999 ohms, replace control,
if it does read 999999 ohms, replace cad cell.
-Expose the cad cell to ambient light (generally enough light to read by is adequate)
If the display shows more than 2000 ohms, short the cad cell terminals,
if the display shows more than 5 ohms, replace control,
if less than 5 ohms, replace cad cell.
If the burner still does not light, proceed to "No Ignition", ERP 20 corrective action.