The pilot valve should adjust up by screwing in the adjustment after removing the cover cap. It should be adjusted to the point where the pilot light is blue and not yellowish. If it doesnt, then go to your Ducane dealer and get the proper orifice and replace it. The reason the furnace goes out is that the pilot light apparently does not have enough flame there to keep the flame sensor satisfied. As for the tech that wouldnt touch it... i would be calling another company. He just wants to get himself a commission on the sale and not repair the issue. Either he is not qualified to work on LP gas or just didnt know any better. If the pilot light adjustment doesnt increase, then going to the next size up orifice may be the answer. A welders orifice file will also do this. If you are having to clean out the pilot orifice regularly then obviously there is not enough pressure being supplied to the pilot, thereby causing the burner lock out or failure.
if this unit has a flame sensing rod instead of a thermocouple, then i suggest also that you take some steel wool and thoroughly clean this rod until its bright and shiny.
This sometimes can cause the failure you speak of
Ok I'm on my way back home to re-install and will advise outcome as well. Thanks for the feedback
hello there, is there anything else i can help you with ?
hopefully that'll take care of it!