Final chapter. Heater, t stat and both pumps were returned for service
and evaluation. Espar control unit was found to be faulty. It was replaced and both pumps tested and work.
Heater was returned and re installed. After 6 or 8 tries the fuel
didn't seem to reach the pump. I assumed their was a vacuum or air lock and was going to try to bleed it the following day. I fired it up just to see if it would work. And it did... now it works perfectly.
All of those who suspected some problem on the "board" they were correct. I received the old one back and it's a sealed unit with an attached wiring
harness. I don't know that it is repairable. Seems that these sorts of components are just replaced... the cost was something like $495. I replaced the exhaust
Thanks to all for their help. It turns out that this was something I could not diagnose... and it was something I could not repair (I suppose I could have ordered and installed the replacement if I was certain that was the problem.
If summer is like winter... the heater will see a lot of use. We're still waiting for Spring!