Aqua Hot not igniting on Monaco Dynasty

Thank you always for the helpful input on the forom. that I really appreciate all the smart posters out there regarding the aqua hot that would not ignite. I kept turning it on yesterday about 5 times, and each time it didn't ignite, I would turn it off. finally at the end of the day it popped on with a big cloud of white smoke And it continued very smoky for about 4 or 5 minutes and then cleared up. since then I have successfully turned it on each time I'm not sure why all of a sudden it started to work maybe, there was air in the fuel line but it's working great now.
Many thanks. Hope it saves me a service call.