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Oil Steam Boiler converted to gas

pitbull2425 Member Posts: 2
Hello guys, I have a question about a Carlin gas burner Model 98629. I have never really had the chance to work on them so not to familiar with the product. The Burnham Steam Boiler model MST396SL-HB. I brought the tstat wire to the TT at the gas burner and that didn’t work . The boiler has a fan control Transformer with the the two black wires for your Thermostat connections. My question is which the correct way to wire that the Thermostat with that burner and boiler. Need Help


  • Robert O'Brien
    Robert O'Brien Member Posts: 3,392
    Burnham doesn't approve gas conversion burners in their oil boilers. Which means most AHJ's feel the same way.
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  • Ironman
    Ironman Member Posts: 6,608
    edited October 2018
    I've you've never worked on one, then I'd highly recommend that you hire someone who does and who knows how to set it up with a digital combustion analyzer.

    As Robert noted, the conversion is not approved by Burnham.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Steamhead
    Steamhead Member Posts: 14,864
    Burnham has never given us a reason for this, therefore their position is questionable at best. I can't see any technical or operational issue with converting that boiler. Any support would have to come from Carlin, and they do a good job of this.

    Now as to your issue- the relay switches 120-volt power to the burner. The thermostat operates the relay. All you need to do is jump TT on the burner and it will start and stop with the relay.

    But this is not a DIY job. Any burner work needs to be tested with a digital analyzer. And a gas conversion needs a double-swing barometric and blocked-flue switch. All this requires a knowledgeable pro with the right equipment.
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Tim McElwain
    Tim McElwain Member Posts: 4,482

    The reason Burnham does not approve converting from oil to gas on their boilers is simply a liability concern on their part.
  • GBart
    GBart Member Posts: 746
    Yeah I think the main concern is that the boiler won't be properly cleaned first.