In preparation for an upcoming trip, and because I haven't fired the heater for many months, I figured I'd fire it for a while at full power just to make sure its working and give it a nice hot burn off.
Press the start button on the Easy Start Timer, and 'NO SIGNAL' is displayed. Hmm. Weird. Never had an issue like that and heater has been installed and running for several years now. Of course, it immediately makes me think communication and then the wiring. But what has changed? Obviously the EST is still getting power to show 'NO SIGNAL'. So looking to the wiring between EST and heater unit. I was recently on some pretty rough roads that could have jostled a wire or connector loose I suppose.
I ended up pulling the seat and swivel, and finding the 3 wire connector coming from EST. Pulled it apart, looked good (clean, no corrosion), but blew it out, and reconnected it. I take a look at the EST and now is showing 'INIT'. So looks like it just re-recognized the unit again. Full menu is back on the EST display.
So with it seemingly fixed, I fired it up and gave it a good run. Hopefully we'll not run into this again anytime soon.
The moral of the story:
'NO SIGNAL' was fixed by disconnecting and reconnecting connector for the 3 wires between EST and heater unit. Leads to diagnosis of bad connection in connector due to vibration.
Hardware Configuration: Espar D2 24V with 12/24 boost supply, Easystart Timer, High Altitude Kit
Plenty of helpful tips in this thread to get me heading in the right direction with the initial troubleshooting.
As always, YMMV