Hi, what happens if this roll out switch is tripping, as it is a safety switch, what will cause a flame roll out is a flue cap missing on your roof, or a bird has nested in the flue pipe this is something you should check. I have had this happen before. Wind will blow down and cause the flame to roll out. Also, if that looks good, a cracked heat exchanger will do this also, but this is a new unit so I will rule this out. The next thing you need to due, is remove each burner one at a time, turn it over and clean it out. To remove one there is a slot at the very back that it will rest in. Raise the back up by grasping the burner from the front, slide it forward over the brass orfice and pull it out, very easy. Do the same when putting it back as you want it to set in the slot in the back, and pull it over the orfice. Make sure your inducer motor is running up to speed and not shutting down on you somewhere in the heating cycle. If it were to shut off, the heater would shut off, so there is no danger. When you smell these fumes, the burners are plugging up and you are smelling this. If your gas furnace is propane gas and not natural, this is a big problem if and when the burners start to plug up. If it is propane and you continue to have a problem, call out you local gas company and just tell them you smell gas. They will check the inlet and manifold pressures for you at no charge. Make sure this flue pipe is clear and please don't forget to rate me and keep me posted in the comment section, I would like to know what you find.
Sincerely,
Shastalaker7
A/C, & Heating Contractor
PS, Propane if you have it, will cause the burners to carbon up, so you need to keep an eye open.