Thank you all so very much. Doug asked most of the questions in the last posting, so here is further information (sorry I didn't give it before):
1. Outside temps are in the mid 50s where we are now (Northern California for our bi-annual medical treatments).
2. I don't remember exactly what he said he replaced, but he had to order three successive units, each of which he tested with his electrical equipment, before finding one with the correct "ohms"--I think.
3. 2005 Newmar Mountain Aire. It is a Penguin.
4. I can't fault Newmar, they've been wonderful on everything with this coach, including building the incredible machine. And the mobile guy is a Dometic certified repairman.
5. We have Aquahot, and while the unit was working in Yellowstone it WOULD switch to furnace at night, as it was supposed to.
Is this any help? Either way, thank you all again.