[Brad Townsend]

Jon, you were correct about the flame detector.
I viewed many youtube videos about similar problems but on house units. Not much on rv units so figured home units are similar and sure enough it was a common problem in home units to have bad flame sensors. I removed and cleaned what was probably almost 30 years of build up on the rod and now it works just fine. Now to do the other unit under the sofa, the worst of the two but no rush for now as the one running keeps us comfy here in the Arizona desert.

I talked to many rv techs and none pointed to this as the problem and most said they wouldn't touch it as most of you are aware the Duo therm has a bad rap for burning down rigs. 

This problem started intermittently over the past few years and got to this point of not firing up and staying on so if others have similar symptoms and have not cleaned the flame sense rod that may well be the problem. It is supposed to be in the annual maintenance list. 

I almost decided to change over to Atwood at a huge expense but no need to now.

Brad