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Won’t fire unless capacitor housing is unlatched

nickmg555nickmg555 Posts: 4Member
Hey everyone! First post on this forum! Now that I have multiple properties and about 9 different heat sources amongst them I figure this forum may be a great place to join! So my first problem although not really a problem because this furnace isn’t exactly necessary but I’d love to have it as a backup! So I have this fairly old oil heater in the basement of my 1850 duplex. It had this ancient burner in it that weights damn near a ton! I replaced it with a burner from an oil fired hot water heater that was down there and not being used. I matched everything up swapped the nozzles and checked the pressure and everything else so it should be a modern version ready to go! However I couldn’t get it to fire! Eventually I put the other nozzle in which is .1 gph higher and 10 degrees less then the one it’s supposed to use and it fires right up and purrs like a kitten and I shut it off so I don’t overheat it due to the wrong nozzle being in there. I put a new .50 gph 90 degree hollow nozzle in to replace the old nozzle and still nothing. Adjust the air to no avail but when I unlatch the spark box on the top and bounce it up and down briefly it fires right up and if I leave it unlatched it runs fine and cycles and works great. If I close this latch and add air it won’t start. I would imagine having it unlatched adds air but if I open the air supply no matter how much it won’t fire unless the spark box is unlatched. I’m a bit baffled. If I push the box down to sit flush the flame immediately goes out. Any oil burner folks have any idea what I’m missing?



  • ZmanZman Posts: 4,896Member
    Combustion analysis?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Jamie HallJamie Hall Posts: 10,469Member
    I don't even know where to start on the list of things which could possibly be amiss.

    I do know that I would want to get a really good oil burner technician in there, with his instruments and all, to work on it. You are essentially doing exploratory work just in figuring out what nozzle (size, configuration, angle, etc.) will work properly, and that is going to take some time.

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • SuperTechSuperTech Posts: 938Member
    I'm sorry but if you own that many properties you can afford to hire a trained professional and shouldn't be attempting something as dangerous as screwing with oil fired equipment that probably should have been replaced a long time ago, and without combustion analysis equipment that ensure the safety of the individuals using the appliance.
  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,802Member
    Opening the transformer will give the burner less air.

    Look, we don't want someone getting hurt. You really need a combustion analyzer and a technician to set this burner up.....if it matches up to the boiler you have size wise etc.

    Oil burners, gas burners, boilers, furnaces and electrical work...they are not hobbies.

    there is a reason for licenses, insurance etc.
  • HVACNUTHVACNUT Posts: 2,184Member
    > @nickmg555 said:
    >I matched everything up swapped the nozzles and checked the pressure and everything else so it should be a modern version ready to go!

    Apparently not everything else.
    Are you a certified oil heating tech? With all your properties you should have a qualified company doing maintenance and repairs. Shy away from the typical slumlord practices.

    How do you know the "modern" burner is acceptable for the furnace? Or is it a boiler?
    The only way to know it's right is with a combustion analysis and smoke test. That's it. End of story.
    If heating is your trade then I apologize, but something tells me your fiddling with things you shouldn't be.
    My mother always said it'll make you go blind.
  • nickmg555nickmg555 Posts: 4Member
    edited January 1
    Let me be clear. I own 2 properties. One of which has several direct vent rinnai propane heaters. This other property is an old duplex. I’m not even close to being some rich prick that your all assuming I am. I have 2 properties and borderline declaring bankruptcy so don’t assume I can afford to have experts out here and on top of that this furnace isn’t even essential. I haven’t needed it in over 2 years of me owning the property. Was just curious as to what it may need to get running. But it doesn’t make any sense that leaving the spark box unlatched will fire but no matter what air setting it won’t fire. This is not a primary heat source or anything that runs when not attended so I don’t want to hear the “don’t mess with It bring in a professional” BS. Absolutely if this was the oil furnace heating the living area I would have my heating guy come out. But this is just some little basement heater that isn’t important at all and more of a curiosity. The question I had was involving why the burner would fire with the top unlatched but won’t fire with any air adjustments. Can anyone answer that? Or will I only get the “pay someone else do it” response?
  • nickmg555nickmg555 Posts: 4Member
    Also the current nozzle is the nozzle the furnace is specified for and set to 100psi.
  • SuperTechSuperTech Posts: 938Member
    Even a little basement heater can quickly produce enough CO to kill everyone inside the building. I don't want to encourage you do something unsafe, especially considering it doesn't sound like an urgent matter by your own admission.

    I advise you to call a pro because considering the the risk factors involved that is probably the least expensive option and the one with the highest probability for a happy outcome for all parties involved.
  • FredFred Posts: 7,863Member
    @nickmg555 Don't be so defensive or offended by what these guys are telling you. They are Pros and they do everything they can (on their own time) to help everyone that visits this site. Sometimes they have to tell posters that they are playing with fire (literally) and the unpleasant biproducts of that fire. It may sound offensive but they also have to assume most posters really don't know how to diagnose and resolve some technical and oftentimes potentially life threatening problems. People don't like to be told they need to get professional assistance. They come here hoping to be able to fix the problem on their own but no one wants to feel like they are offering assistance that is counter to ensuring the safe operation of what can be dangerous installation/implementations. They are trying to give you good advice. Accept it for that, even if it's not what you want to hear. I realize this is not your principal source of heat but all it takes is one use to be catastrophic. The fact you took a burner out of another appliance and installed it in this one, I am sure set off alarms. It may work or it may not. The unit and these guys are telling you something isn't right and without a combustion analysis, no one can determine what is wrong.
  • HVACNUTHVACNUT Posts: 2,184Member
    I've been servicing oil systems for over 30 years.
    What's a spark box?
    If you want it to run properly, you cant afford not to have an expert out to look at it.
    Sorry to upset you, but nobody here will help someone troubleshoot a problem if they're not experienced or have the correct tools and instruments to do a proper repair. Sometimes things go BOOM!
    I certainly wouldn't sign my name to it.
    I.M. Fletcher
  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,802Member
    Well said @Fred
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