New Furnace, loud bang, no heat
We just got home from picking up our new 2022 199MBS. We tried the furnace 3 days ago and it ran and heated, but the CO alarm went off (though there was accidentally a plastic garbage bag partially covering it at the time) so we thought it might just be a fluke. This morning I thought we would try it again since we are home and parked for a couple of weeks. I turned on the propane and then the furnace and it immediately came on but was blowing cold air. After about 3 minutes, it was still blowing cold air and then there was a significant loud bang or explosion. The furnace continued to run and I could smell the typical fuel burn and some slightly warmer air for about a few seconds, but then cool air again. I turned off the furnace and it ran for about 2 minutes and then shut down. Now, when we picked up the RV, it was about 900' elevation and here at our home it is 8500', so are there any adjustments I can make or need to make here or what might cause that load bang?