Thanks Peter. It was a pleasure to spend time with you and Katherine last week!

So, this raises the question, as to why the SMX controllers are programmed to do "something" at 40 degrees. I have only roof airs, and my Marathon manual specifically states that the ac heat pumps are disabled below 40 degrees.

If it's simply a matter of changing the programming on the controller, why did they limit things at 40? Surely there must be some reason?

I spoke to someone (I think it was Kevin) who indicated his cruiseair heat did indeed turn-off in the middle of the night when things got cold enough.

Ray