Old Biscuit I concur with what you have stated. I also am running the Refer on Electric. I had not thought about the electrode that ignites having a mis adjustment but there may be something going on there I do smell that whiff of propane from the furnace vent even when the furnace did not light.
Last night after I posted this topic, I shut off the electric for the WH and turned on the gas button. This morning when I got up I turned the furnace on and it fired right up. I think I can leave both the electric and the propane turned on at the same time for the WH nothing in the manual says otherwise.