On our second trip we couldn't get the tankless to work properly. In hindsight it was probably because I only opened the spigot two turns, so not enough flow/pressure for the sensor to light the burner.
Went to Cassini Ranch this past weekend and I think I finally found the sweet spot.
We use a regulator that tops out at 40psi. Opened the spigot all the way and, like mentioned above, and by "The RV Tech" only use the hot water knob and adjust the temp on the panel. Once I figured that out, it was gravy.
One issue they have is they're usually last in line on the propane loop. Running the stove or furnace for a minute or two after setup ensures the system is pressurized with gas and all air pockets have been purged.
Another is, as mentioned, running the cold water, using it to regulate the temperature interrupts/decreases the flow of water through the tankless, dropping the pressure and causing the burner to go out.
Both of these issues will cause an E1 error on the panel.
If you're in the shower or running the sink faucet, just hit the temp up/down button and wait a sec for the water to come back up to temp.
Had a nice long, hot shower on check out day.
