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Nat gas to LP conversion

Jon951 Member Posts: 16
I saw this post on another forum, but the guy's questions weren't answered:

"Can you tell me what would happen if a Navien boiler was installed but not converted from natural gas to propane gas. Would the boiler still work for a time? And then what would happen.
We had a Navien boiler installed in May, 2017. It was only used to heat water at that time as it was in the warmer season. But then in November, 2017, my mother and I succumbed to carbon monoxide poisoning when levels reached 1800 in the middle of the night and by the time I heard the alarm, I was already unable to do anything to get help. Luckily, help arrived when my daughter was unable to reach me and suspected something was wrong. We were taken by ambulance and spent 8 hours in a hyperbarrick chamber".

"We (the original authors of the post) suspect that the boiler was not converted to propane gas. Is this basically what would happen if a boiler was not converted"?

Just curious myself about the effects of running a boiler purchased to run on Nat gas, was run on LP. Would there be any obvious signs such as the smell of LP from too rich a mixture? Would the boiler run for a while and fail?


  • Icarus
    Icarus Member Posts: 143
    Natural gas and LP are different animals. LP requires higher pressure and smaller orifice sizes to run properly. Natural gas runs ~7” of water column, propane ~13”. My guess is that if you try to run an LP unit on Natural, it might fire but would perform poorly. Running a Natural unit on LP would be dangerous as it is designed (or at least regulated) for lower pressure. That said, My guess is that the Navian would not fire under either circumstance as it is electronically controlled and would recognize the incorrect pressure and shut down?

    I certainly would leave it to people way smarter than me to opine, but your related experience suggests that under no circumstances would it be a good idea.

  • icy78
    icy78 Member Posts: 404
    This is just my opinion, but I think you need to get somebody out there that's able to determine the C0 source. And, the reasons for the C0. And the remedy.
    It appears to be a cut-and-dried situation of incorrect combustion setup but there are other factors in play as well.
    Venting, windows, negative building, freshair intake, unused exhaust intake......other equipment.

    For instance if you are producing extremely high amounts of C0 and you have a two pipe system that's venting outside, how did it get in the house?

    Quote... I was already unable to do anything to get help...!!!!

    I'm glad that you two are alive it could easily be the other way. It's a good time to look into low-level Co alarms and not trust those UL 2034 alarms.
    Read up on both kinds. I think you're lucky to have been saved this time.
    delta T