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O/T Furnace Flame Sensor Trouble

Discussion in 'Uncategorized Threads' started by chessney, Feb 5, 2008.

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  1. chessney

    chessney TS Member

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    Jan 29, 1998
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    I have a Frazier-Johnson (York) unit.Model # PBNU-LD12n080d. For the last 4 years I have put 8 new flame sensors in.After about 1 or 2 months of use it will fire up and shut down right away. I tried cleaning the sensors,but it didn't help. I put a new flame sensor in and it will last another 2 months. I originally replaced the electronic box, but that was not the problem. Any thoughts on this would be very helpful....Chessney
     
  2. MGRAY

    MGRAY TS Member

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    Sep 30, 2006
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    Hi, I had the same problem. A furnace guru told me that this is a common problem. More so if dry wall dust is cycled through your furnace. Normal house hold dust will cake on the sensor. It needs to be taken out and polished with scotch brite pad. I do this once a year now, and have not had a prob. Good luck. Marty
     
  3. yenko

    yenko TS Member

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    Jan 29, 1998
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    cleaning with scotchbrite or 180 grit paper is fine,be sure the sensor is in direct line of flame from burner and that the flame does not bounce around and cause low micro amps anything below .4 micro amps will produce same problem.
     
  4. jackmitch

    jackmitch TS Member

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    Jan 29, 1998
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    i prefer a wire brush for cleaning flame sensors myself. actually i prefer thermocouples and standing pilots, those were much simpler and cheaper to fix. i had a service rep from lennox tell me once not to use sandpaper but it was so long ago i can't remember why.when i started working for my dad he said if you had a thermocouple, a gas vave ,blower motor, and a t-stat in your truck you could fix about anything.when i quit i had a small fortune in repair parts and always worried i wouldn't have the right one.jackmitch
     
  5. chessney

    chessney TS Member

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    Update: I tried all the above mentioned to no avail. I had to call a service man. He tested the control panel and sure enough, the most expensive part on the whole furnace was bad.He put a new panel in and it works fine!..Thanks for all the help..Chessney
     
  6. Ljutic111

    Ljutic111 TS Member

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    I was told that if your furnace is near the washing machine in the basement to only use liquid detergent because there is something in the powdered soap that makes the flame sensor or the igniter to go bad . If the powder gets airbourne and gets on those parts it will lower the life expectance . Happened to a few people I did work for .
     
  7. keennt

    keennt TS Member

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    May 5, 2007
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    I have a Beckett burner in my well-mclain fuel-oil boiler......
    It would not fire after after a few cycles....I would clean the flame sensor, adjust the electrodes....it would run good for day or two, same thing over and over.....I changed the sensor, I changed the 'brain box'....still acted up....I talked to a furnace guy and he said to make sure the insulating porcelin on the elctrodes was clean...no soot, just nice and white....He said to sand them clean.....I did that, and low and behold, it hasn't missed a beat.....runs good......he said that any carbon tracks will cause the problem of kicking out, or not firing.....the electric current will jump across the dirty insulators.........Ken
     
  8. Primedust

    Primedust TS Member

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    Jun 7, 2006
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    472
    Many furnaces are installed in basements or small rooms. In some cases the MRS. tries to store floor cleaners, soaps, ammonia cleaners, etc. around the house in the same room. Not only will it mess up the flame rod, but it can destroy the heat exchanger and cooling coils as well! Some cleaners when burned are very corrosive and cause carbon or sooting and insulating effects to the flame rods. Best thing is to keep the cleaners well away from the furnace. Many furnaces are in laundry rooms. Try to have the furnace off when doing laundry as much as possible and save some headaches. Just having ammonia cleaners in the house is enough for some units. Sure would be nice to be back to the old reliable $4.00 thermocouple. You could get those at the hardware store and save a 200 or $300.00 service call.
     
  9. Dr.Longshot

    Dr.Longshot Banned Banned

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    Jan 29, 1998
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    5,722
    Invest in a good digital volt-ohm meter so you can read the millivolt output of the flame sensor and see if it falls in the guidelines of thr mfgr. if it does the electronic ignition module is the problem, as suggested by previous post install a ground wire from the burners to the furnace framework ground wire where the electronic module ground is located. Best to use scotchbrite pad to polish the electrode. There were some problems with the WHITE ROGERS control and the replacement has been updated,I will bet a dollar to a donut that the replacement unit had a different model Number, and fit more styles of ignition controls.


    Gary Bryant
    Dr.longshot
     
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