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Converting Oil Boiler to Run on Gas

28W Member Posts: 141
This is a moot question for me, since I've already replaced my oil boiler with a new gas one, but since I've read various posts on the topic, I am curious.  How well does it work to take an oil boiler and convert to run on gas?  I assume you will need to keep the water temperature high to prevent condensing, so you will lose some efficiency there. 


  • Tim McElwain
    Tim McElwain Member Posts: 4,588
    The answer is

    you can run the boiler the same way you did on oil. You will have pretty much the same combustion efficiency perhaps a little higher. Normal range is 80% to say 86% depending on the boiler and what burner you use. Then it is up to the experience of the installer to be able to get the unit to its maximum design efficiency. As long as the flue gas temperature does not go below 275 degrees no condensing will take place. Most gas conversions run at about 350 to 450 degrees again depending on the package and the venting system itself.

    Then the other consideration today is the difference in cost of fuels and the big question will gas remain as the low cost fuel in the future.
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