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using gas boiler for propane

WickedAce Member Posts: 1
This is a two parter. First; I came into a gas fired hot water boiler last spring that has low miles. I want to use it to replace the electric baseboard in my house with, you guessed it, hot water baseboard heat. I was told but would like to confirm I will need to replace the orifice in the gas valve to accommodate propane. Is this the case?

Second; does any know of a calculator that can determine the energy in an engineering unit of different sources? I.E. electric- btu/kwh, gas- btu / scfm, propane- btu / gallon.


  • EricAune
    EricAune Member Posts: 432
    Heres some numbers from the MN mechanical code


    1 KW = 3,413 Btu/hr

    Natural gas:

    1 Cubic Foot of Natural Gas = 1030 Btu's

    1 CCF = 100 Cu Ft = 1 Therm = 103,000 Btu's

    1 MCF = 1,000 Cu Ft = 10 Therms = 1,034,000 Btu's = 1.034 MMBtu's


    1 Gal Propane = 91,600 Btu's

    1 Cu Ft Propane = 2,500 Btu's

    You can also check this link:\

    "If you don't like change, your going to like irrelevance even less"
  • TonyS
    TonyS Member Posts: 849
    First you have to convert

    the gas valve. If its convertible, some you just change a spring, others you flip the spring and reset the spring pressure, it depends on the valve. Next you have to change the orifices to each ribbon burner. you can braze them and then drill 7 numbers(drill sizes) smaller. This will get you close to the original input. The best thing for you to do is call the boiler manufacturer and buy the proper kit. Propane is heavier than air and will fill a room up before it ignites. Usually there is nothing left from a propane blast. Best to leave it to a professional.
  • Tim McElwain
    Tim McElwain Member Posts: 4,518
    Converting is something that

    should be done by a professional. Do you purchase propane from a local propane dealer? If so many times they will do the conversion for you.

    It requires an exact calculation to determine orifice size for each burner. Or you can contact the boiler manufacturer and give them Model and Serial number and they will send a kit.

    The gas valve will require the regulator to be converted also to propane.

    The pilot orifice also has to be changed.

    There should upon completion of the conversion be a combustion analysis done to determine maximum firing rate and establish the most efficient operation possible.
  • Empire_2
    Empire_2 Member Posts: 2,343
    edited September 2009
This discussion has been closed.