John, That diagram and picture is wonderful. Hope it is like the LY.
My heater that was messed up pretty good is now providing heat! I am told that it if it ever returns to a temperature here in Arkansas above that of this ridiculus cold spell the system will even make cold. It is amazing how we now take for granted that heater in the front of MHs. I certainly learned the importance of keeping our units out of the hands of unqualified persons claiming to be RV specialists. It took a dealer that has trained GM, Chrysler, and Airstream personal on staff working with the airstream factory people to get it going again. What a mess. This was due I believe to a technician who destroyed the heating system in his attempt to haywire a fix. You know, the kind that cuts things out because they are causing a problem and you don't really need them anyway. The lesson learned is find sombody you can trust thru references. Best yet, learn the systems yourself so you can avoid what happened to the previous owner of my rig. Did I tell you how nice it is to have heat and cool at the touch of a lever and a few buttons. Thanks to this forum for all the good information.