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Any dual fuel boilers out there ?

some customers have asked us if the oil boilers we install can be fitted with a gas burner , if they decide to switch . Working for an oil company , I try to disuade the homeowner from this line of thought - over the long haul , oil has been a greater bargain on L.I. But I'll try to answer truthfully to an honest question .

Do any new oil boilers come dual rated ? And do the AFUE ratings compare from oil to gas ?


  • techheat_2
    techheat_2 Member Posts: 117
  • Have not seen

    a residential dual fuel burner since SunRay kicked off. They had a GC 210 that worked well in mid size residential boilers. A little noisy on gas. The kicker is the control scheme & cost for the gas-oil combo. Though Carlin is getting close w/ their little blue box.

    Gordon-Piatt makes the S4 which starts @ 1.50 gph & 210 cfh gas. Riello's RLS starts @ 2.7 gph. Powerflame's CR1 starts @ 2.5 gph. All are pricey, parts prices are high, and few residentially oriented companies will work on them.

    Consumers' best bet is still an efficient, serviceable, well installed unit. The future cost for a btu will be about the same. Oil, gas, propane, or buffalo chips.
  • doug_16
    doug_16 Member Posts: 62
    And I have two,

    one for each fuel if the pipe gets extended up main street.
    The co-gen plant in town uses 93 million cubic feet a day but there is no distribution in town at all.
  • joel_20
    joel_20 Member Posts: 4

    The Vitola 200 can go both ways. What's nice is the gas burner has been tested and approved by the factory. You can actually order it set up that way. That's nice because with most equipment your being asked to retro fit in a generic burner ,and we all know the headaches that can bring.
  • Joel

    Does the AFUE differ between the gas and oil version of the Vitola 200 ?
  • Techheat and Doug

    Does it specifically state in the boiler literature that a gas burner can be used in a Biasi ? I know the boilers we install do not state it and would wonder about liability if it is not in the specs .
  • I didn't mean a dual fuel burner

    I'm thinking about a dual fuel boiler . I used to switch out a Riello M5 for a used Wayne gas gun in a crappy Repco . It was in my old bosses rental home when the tank would run out of oil . Took about 15 minutes a swap with flexible connectors .
  • DaveGateway
    DaveGateway Member Posts: 568
    Yes the B10

    install manual has gas burner settings. The SG series should have been certified by now. There are a few other makers like Thermodynamics offer a boiler fitted with a Heatwise or Carlin gas burner. Normally, these are only low 80% AFUE boilers though.
  • S Ebels
    S Ebels Member Posts: 2,322
    About 3-4%

    Oil is rated about 3-4% higher AFUE. I don't know if that really means anything though as every Vitola I've ever tested came in a minimum of 2% higher than the AFUE. I've seen 88-89 on mine when firing into 100 degree water.
  • Any conversion of an oil

    to gas should be done only with approval from the boiler manufactuter. That is the way to be safe. I have converted many oil boilers over to gas in the past and typically found my combustion efficiencies could usually be 80 or higher depending on the boiler. Some boilers are set up to be dual fuel boilers and fire equally well with oil or gas.

    I have used gas power burners such as Carlin G3 series up to 180,000 BTU's with good results. Economite burners do well up to 300,000. Riello gas burners are very set up sensitive and need real experience with gas burner set up.

    When you get above 400,000 BTU's you need to be careful with the gas burner choices. Some burners and boilers do not match up well.
  • Robert O'Connor_6
    Robert O'Connor_6 Member Posts: 299
    Thats a can of worms Ron Jr

    that you wouldn't believe.

    Timmie maintains that any oil boiler can be gas fired because gas conversion burners are built to an ANSI standard.

    As much as I respect Timmie . I question whether a boiler that is UL Listed for oil can be fired with gas.

    The Biasi's are offered both ways and I think the answer is yes A while ago only the Riello gas burner was "listed" as a package in the Biasi. That may have changed now. They have always offered Carlin.

    This whole business of "listed " and "approved" can be very subjective



  • For some reason

    I was under the impression that the gas burner manufacturer , or the gas supply company took over responsibility of the equipment it was connected to . Might have been heresay or something I just assumed on my own . It's been a long , long time since I installed a gas gun . Thanks Robert and Timmie for the enlightenment .
  • Robert O'Connor_6
    Robert O'Connor_6 Member Posts: 299

    do you recall the extensive correspondance we had on this issue a few years ago?

    I think we are on the same page now.

    All the best


  • mark_40
    mark_40 Member Posts: 65
    news for Timmie !

    a boiler must be listed for the fuel it burns .... an example of an oil boiler not approved for nat gas is the Smith Mills boiler .. due to the casting design , there is no natural draft path to vent gas if there was a leaking gas valve ... therefore the appliance is only listed for oil , changes are needed for gas ..
  • Ron a lot of gas

    companies in the past would change over to gas on old coal systems and on oil design boilers. It was pretty straight forward on residential burners under 400,000. We did thousands of them. I have personally installed well over 3500 conversion burners in my career. It really requires a lot of experience and I will be the first to say that not every boiler can actually be converted. The gas company back then took full responsibility for those conversions.

    It is obvoiusly still a business being done today or Carlin, Midco, Heatwise, Wayne and others including Riello would not be selling burners.

    The installation of conversion burners and the burners themselves fall under an ANSI Standard for installation and burner design.

    I will not put them in myself anymore without approval from the manufacturer of the boiler. I just do not have enough insurance to cover the liability.
  • Yes Robert I do recall

    our many e-mails. I have sort of made it a policy now days to seek approval from the boiler manufacturer before converting any oil over to gas. As I posted my insurance does not cover me otherwise. I have recently replaced some existing conversion burners with new ones and refurbished the boilers and done a new combustion analysis on them.
  • I agree Mark, I have

    however been able to receive permission to convert some residentail oil systems over to gas.

    Commercial and Industrial boilers are a different situation.
  • Robert O'Connor_6
    Robert O'Connor_6 Member Posts: 299

    cahracteristics of the latest generation of modern oil boilers are a bit different than they were 15 years ago. Lots of the modern euro's are three pass and have a large pressure drop thru the fireside. Pressure firing is the rage with these rigs. So I suppose that changes what you would use for a gas conversion burner?
This discussion has been closed.