Smelly Water Heater

And 8,900 feet isn’t much on either side of the Sierra. 

at 8900 ft your also going to get incomplet combustion on what ever your trying to burn.  removing the lid and seeing a strong blue isn't a good indicator, as when you take the lid off it allows more O2 to get to the combustion process than normal so it could make it appear better than it is.  at that altitude you are taking about a 35% hit on the effenciency of the water heater and it can still have incomplete combustion that isn't aparent.  

look at all the openings around the water heater.  open them up make sure everything is sealled up good.  one little spot missed can let the gasses in, especialy at higher altitudes

No RV is airtight, nor should it be. Is it enough to set off the LP detector? Is the detector working? I have had some batches of LP that contain more smell than others. LP has no smell. It's added to detect a leak and sometimes more gets added for some reason. 

how close is the stove, fridge and furnace to the sink?  They all have propane going to them.  

This is my first RV and I’m getting that same smell! I couldn’t figure out where it was coming from! I have a Geo pro 20FKS, gonna shut off my water heater and see if that smell go’s away. I’ll update tomorrow.