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Delayed ignition gas furnace Lennox G20

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Hello
u have a furnace that is only having delayed ignition on the right side of the furnace. The e- ignitor is just a little on the left side and the strange things is after it does it once, it won’t do it again until a while later. 
I had a service company come and look at it. They cleaned it and said it’s working properly now. But when he left, I waited a bit and it’s doing it again. 
Does anyone have any advice as to what it could be. ? 

Comments

  • Alan (California Radiant) Forbes
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    Check the gas orifices on the burner. It's common for spiders to build an egg sack there during the summer and common for the owner to find out in the Fall at the beginning of the heating season.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
    Erin Holohan HaskellHVACNUTTeemok
  • HVACNUT
    HVACNUT Member Posts: 5,855
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    We're the burners removed and checked/cleaned? The crossovers could get crusty over time, especially in a humid environment. 
    SuperTechAlan (California Radiant) Forbes
  • brentnormandin
    brentnormandin Member Posts: 7
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    I had a HVAC tech that blew everything out with a compressor and air gun. Then he charge me $150 to do that. I could have done that. He said all is good and left. It's still doing it.

    And no the burners weren't removed. The HVAC person is supposed to come by this week and said he's going to have to pull all the burners out and drill them. And if that doesn't work he's going to order new burners. Does that make sense to you.
    Is it difficult to pull the burners out on this system. I've seen other models that look easier than this one.
  • brentnormandin
    brentnormandin Member Posts: 7
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    And by the way, thank you for your comments.
  • brentnormandin
    brentnormandin Member Posts: 7
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    And for some reason, after i get the delayed ignition on starting the furnace for the first time after sitting for a while, if I shut it down and then start it right back up, it starts up perfectly fine.
  • JUGHNE
    JUGHNE Member Posts: 11,074
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    How about a picture of the burner compartment showing all the items you mentioned?
  • Teemok
    Teemok Member, Email Confirmation Posts: 511
    edited October 2023
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    As HVACNUT said, if the jets are clean, this is likely a crossover corrosion/clogging problem. While some types can be cleaned with care and diligence others are damaged and or of of poor quality and can become a hazard. I would not want the same person to returning that failed to identify this common problem the first time. The intermittence is often from differences in air draft flows and burner temperature changing gaps and orifices. New burner tubes are the safest bet if they are still available. This is an older natural draft furnace that, unlike it's very thick steel predecessors, was not designed to to last indefinitely. The heat exchanger should be well inspected for cracks and general condition by an experienced tech before investing in new burners. The flue and the bonnet condition should be scrutinized. "Drilling out" can mean a lot of things and some of those are not good. Consider a new high efficiency furnace. It could save you substantial chunk of money yearly depending on how much fuel this one is currently burning. If the new unit is of good quality it should be better, safer investment if it's sized and installed well.
    Alan (California Radiant) Forbes
  • Pipestretcher
    Pipestretcher Member Posts: 6
    edited October 2023
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    Was the gas valve checked for pressure? Does the pressure fluctuate when operating? Wondering if it's not in the burners you may have a restriction in the line or valve. Any work done on the gas line over the summer? Any construction done on the house?
  • brentnormandin
    brentnormandin Member Posts: 7
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  • brentnormandin
    brentnormandin Member Posts: 7
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    Thank you for all the replies. In the fifth image. Where the ignitor is, the flame has no problem running down the rail to the left but does not run down the rail to the right. And thus, the reason for the delayed ignition.
    To note:
    - the pressure does not fluctuate and has not been checked no work has been done to the house.
    - I would love to buy a new furnace...what do they cost these days? I just started a business and it's very challenging financially right now. Obviously my families safety comes first but if I can get by with a safe fix for now, that's the better option for me until my business gets going.
    - I think that you're correct and this is the issue " if the jets are clean, this is likely a crossover corrosion/clogging problem"
  • JUGHNE
    JUGHNE Member Posts: 11,074
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    IIWM, I would pull the burners out and clean the crossover channels.

    And check the jets for obstruction as mentioned above.

    Also, does the pilot flame put flame to the left and right?
    The pilot burner may need cleaning also.
    Teemok
  • brentnormandin
    brentnormandin Member Posts: 7
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    OK thank you for the advice. The flame shoots to the left but that's the direction that it's aimed and is fine light correctly after the first ignition.
    I am a salesperson / business owner but I do have a lot of experience working on cars and everything else.
    Is it a challenge to pull the burners and clean them?
  • HVACNUT
    HVACNUT Member Posts: 5,855
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    OK thank you for the advice. The flame shoots to the left but that's the direction that it's aimed and is fine light correctly after the first ignition. I am a salesperson / business owner but I do have a lot of experience working on cars and everything else. Is it a challenge to pull the burners and clean them?
    Um, it's not a challenge until something goes wrong. Then what? A gas heating tech old enough to know what they're looking at would be nice.
    Alan (California Radiant) Forbes