09 F 250 blowing white smoke

So my 09 F 250 with less than 30,000 miles has started blowing white smoke out of the tail pipe! It's not all the time, just sporadically. This all started after it tried to go into the regen mode but only popped up on my display for a few seconds. Any thoughts on what this is? The dealer seems to think it's no big issue until "it starts happening all the time or the check engine light comes on" Not so sure what I think about that. Any feedback would be appreciated.

Thanks

Chris