Takagi tk3 flash igniter woes

HEY, GUYS:
I bought a Takagi TK3 about 2 years ago and the igniter goes out. I'm a retired car mechanic/fabricator/machinist, etc.
So, what is the programming in the processor for operating the igniter?
What are the timer limits, and what keeps the fire lit?
How does the flame rod and fuel mixture rod work?
Where does the ignitor rod fire the spark to?
My trouble codes are:
111 no fire
121 fire went out.
My unit is outside mounted in the screen porch of my remodeled bungalow. Propane unit, city H2O
Help me out guys, I need takagi parts and advice, I'm dying out here!
HANK WHITE PH 530-357-3246

Sounds like a flame detector problem. Look in the manual to figure out where the flame detector (item 106, page 35) is inside the unit. Turn off the power and gas before diving in. Take a ScotchBrite or similar soft plastic scouring pad and buff up the business side of the detector,see if that keeps it from recurring.

Flame detectors are susceptible to chemical contaminants in the combustion air- if it's outside an open kitchen window pr range vent where you're putting a lot of suspended fry-o-latorgrease in the air or something you can bet on it having an issue sooner or later.

Word is Takagi has a pretty good help line- they'll talk you through almost any diagnostic issue.