Page 1 of 2 12 LastLast
Results 1 to 13 of 24

Thread: ignitors

  1. #1
    Join Date
    Feb 2006
    Posts
    3
    I'm not an HVAC tech., and I'm not asking how to repair my furnace. The ignitor for my 1998 Miller gas furnace has gone bad 4 times in 2 years. I've had the same service replace it every time. Two months ago another standard one went bad, and it was replaced with a nitride ignitor. The service tech said he didn't believe that one would ever go bad. But it did--yesterday--and the same tech came out and replaced it free-of-charge today. When I asked the tech why these keep burning out so fast, he shrugged his shoulders and said, "must just be a bad one in the bunch". I appreciate their service, but I'm not sure if they know what's causing my problem. Does anyone here have any ideas? Thanks.

  2. #2
    Join Date
    Mar 2004
    Location
    SE Michigan
    Posts
    18,209
    Have them check the inlet and outlet gas pressures and post them on this site. LP or Nat. Gas?
    To put the world in order, we must first put the nation in order; to put the nation in order, we must put the family in order; to put the family in order, we must cultivate our personal life; and to cultivate our personal life, we must first set our hearts right.
    -- Confucius

  3. #3
    Join Date
    Feb 2006
    Posts
    3
    It's natural gas. I think they have checked those pressures. I don't know what they were. I think he said there wasn't a problem there, or the furnace would be unsafe to use. It also had a roll-out switch and circuit board replaced last month for another problem. If I have them come back again I have to pay;-)

    [Edited by drc6888 on 02-02-2006 at 08:30 PM]

  4. #4
    Join Date
    Mar 2004
    Location
    SE Michigan
    Posts
    18,209
    I would look at the gas pressures and even the burner oriface size and make sure they match the specs. In addition, the voltage to the ignitor should be noted. All these things should appear on the service ticket if they checked them. I would exspect nothing less. If they did not record them, then how is another company tech going to know what the previous tech did?
    To put the world in order, we must first put the nation in order; to put the nation in order, we must put the family in order; to put the family in order, we must cultivate our personal life; and to cultivate our personal life, we must first set our hearts right.
    -- Confucius

  5. #5
    Join Date
    Dec 2004
    Location
    Robards KY
    Posts
    269
    If your furnace control board originally had a silicon carbide ignitor and it was changed with a silicon nitride ignitor, they need to go back to the carbide ignitor. The nitride ignitor starts out using 120v,but is designed to lower the voltage to it( as low as 80v) or as low as it will no longer ignite the burners and stayat that voltage.That may be why that ignitor failed. Others on here may be able to explain better,but for a short answer I hope this helps.

  6. #6
    Join Date
    Feb 2006
    Posts
    3
    There is an inspection and cleaning checklist on the ticket, but nothing was recorded. I'll call him tomorrow and see if he happens to remember what the pressures were, and burner orifice size. Thank you for your info.

  7. #7
    Join Date
    Mar 2004
    Location
    SE Michigan
    Posts
    18,209
    I dont understand why a tech would take the time to check these items and not record them. Unless he didnt check them and is just a parts changer which my 5 year old son can almost do. Good luck to you!!

    In addition, if he checked these items and didnt record them, then how can he justify the time spent on the job to the service manager?

    Sounds fishy to me

    [Edited by coolwhip on 02-02-2006 at 09:39 PM]
    To put the world in order, we must first put the nation in order; to put the nation in order, we must put the family in order; to put the family in order, we must cultivate our personal life; and to cultivate our personal life, we must first set our hearts right.
    -- Confucius

  8. #8
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,516
    there is a reason for that many ignitors. 4 in two years is way to many. 1 every four or five years would be somewhat reasonable. you need to inform them you want the problem found. at the same time make them put back the ignitor that is designed to be in the unit not one they think will compensate for the problem. Aparently it isnt compensating.

    is the unit short cycaling. turning on and off every few minutes.

    is it going off on high limit where the burners turn off and the fan keeps going. this can be viewed easly just by watching the unit run and see if the burners turn off and then come back on a minute or two later.

    is the unit in a high humid eara where the ignitor stone can absorb excessive moisture in the summer if so but in a dehumidifier to keep the moisture down and run the furnace once a month just enough to get the ignitor hot and then turn off

    is the voltage proper or not and is it grounded properly
    have them clock the meter to make sure you have the proper imput btu. checking the gas presure doesnt always tell you everything. you may still be overfiring and his mamometer may be off.

    a combustion analiser will help also to make sure it is burning properly and not impinging on anythig causing imcomplete cobustion and excessive moisture on the heatexchanger and ignitor

    there are tests they can do to find the problem instead of just changing parts. the avarage furnace over a twenty year life should only have three to five ignitors imo

    [Edited by tinknocker service tech on 02-02-2006 at 09:59 PM]

  9. #9
    Join Date
    Jan 2006
    Location
    salisbury, md
    Posts
    29
    Originally posted by tinknocker service tech
    there is a reason for that many ignitors. 4 in two years is way to many. 1 every four or five years would be somewhat reasonable. you need to inform them you want the problem found. at the same time make them put back the ignitor that is designed to be in the unit not one they think will compensate for the problem. Aparently it isnt compensating.

    is the unit short cycaling. turning on and off every few minutes.

    is it going off on high limit where the burners turn off and the fan keeps going. this can be viewed easly just by watching the unit run and see if the burners turn off and then come back on a minute or two later.

    is the unit in a high humid eara where the ignitor stone can absorb excessive moisture in the summer if so but in a dehumidifier to keep the moisture down and run the furnace once a month just enough to get the ignitor hot and then turn off

    is the voltage proper or not and is it grounded properly
    have them clock the meter to make sure you have the proper imput btu. checking the gas presure doesnt always tell you everything. you may still be overfiring and his mamometer may be off.

    a combustion analiser will help also to make sure it is burning properly and not impinging on anythig causing imcomplete cobustion and excessive moisture on the heatexchanger and ignitor

    there are tests they can do to find the problem instead of just changing parts. the avarage furnace over a twenty year life should only have three to five ignitors imo

    [Edited by tinknocker service tech on 02-02-2006 at 09:59 PM]
    I have to agree with you on that one. They have put way too many ignitors in there. ask to look at the old one when tey take it out see if there is a sign of a finger print or a odd color in one place.

  10. #10
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,516
    soccer
    you know i never thought about prints
    i just assumed everyone knows not to touch the stone
    could be as simple as that

  11. #11
    Join Date
    Nov 2001
    Location
    east kansas
    Posts
    8,038
    Touching the ignitor does not shorten their life. According to the class I had on ignitors.
    Beware of advice given by some guy on the Internet.

  12. #12
    Join Date
    Nov 2001
    Location
    east kansas
    Posts
    8,038
    I have a nitride (?) ignitor made to replace the Carbide ignitors. Come with adapter kit and ignitor. Says in the instruction that it need 120 vac.
    Beware of advice given by some guy on the Internet.

  13. #13
    Join Date
    Nov 2001
    Location
    east kansas
    Posts
    8,038
    Is the ignitor shutting off after it lights the burner?
    Beware of advice given by some guy on the Internet.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event