Thanks tracman
I am in Georgia and it got a bit nippy last night. I have heat strips in both a-c units so we got along.
The two vents are on opposite sides one rr and one mid left. I have not found individual shut off valves but I did find interior access areas in rear closet and under sink.
I guess I will have to pull the outside panels to see what is really there.
I tried the purge cycle manually since the original documentation says to do it manually. I tried to run it after but I did not know there might be an auto purge cycle. Didn't wait 5 minutes because I got no heat.
I will try again with more patience
If not I guess I will wait until we get home tomorrow to investigate by pulling the panels. We can get by with the heat strips for a day.
This will be the final trip before we winterize so I guess I can defer mx until we get home
Thanks again - finding out how everything works has been an interesting experience. I have all the original docs and schematics but they leave a lot to be desired.
May the road rise up to meet you ---
Jim