You got the Recall Box (circuit board) WET and it tripped (RED LIGHT ON is tripped condition)
As suggested check burner area for any yellowish residue or signs of leak.
Reset the Recall Box by using a strong magnet placed against the front of box near top and slowly move it back/forth listening for a click (reed valve resetting---RED Light OFF)
The Recall Box is attached to absorber tube with clamp....simple/easy place to mount.
TILT the Face of Box DOWNWARD. Helps keep moisture out of the open slot on face