Furnace Help

Discussion in 'Shop Talk' started by ChickenHound, Nov 30, 2005.

  1. ChickenHound

    ChickenHound Well-Known Member

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    So I come home and it's 53 degrees in my house for some unexplained reason.

    (I know nothing about furnaces, so please excuse my simplified description here): The burner element on the furnace will come on, then a flame will come on for 3-6 seconds, and go out. Then the burner element goes out. This process repeats 2-3 times before the furnace sits idly doing nothing. The fan never comes on, ever. The flame only runs for a few seconds each time.

    If I set the thermostat fan setting to "on" instead of "auto", the fan still won't come on... Nothing coming from my vents...no noise coming from the furnace.

    It's a propane/gas furnace - plenty of propane in the tank, other gas appliances working fine throughout the house.

    Any ideas??? It's freezing in here! :help:
     
  2. Cabin Fever

    Cabin Fever Life NRA Member since 1976 Supporter

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    Is there a little "window" on the wall of your furnance that allows you to see a flashing light? If so, count the number of long and short flashes....this is a code. Look up the code in your owners manual. Sometimes there is a chart right on the furnance that tells you what the code means. Looking up the flash code will tell you what the problem is.
     

  3. ace admirer

    ace admirer Well-Known Member Supporter

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    ok "burner element" would that be the spark?



    if you are getting spark, then a flame, which then goes out, the flame sensor is probably not "seeing" a flame.. it could be a photo eye, a flame rod, or thermocouple or maybe the problem is the flame is not of good enough quality to be sensed. that could be worn or stopped up nozzle or "Z" distance or probably a dozen other things i don't know about.

    most becket burners have a photo eye, which might have carbon soot on it and blocking the eye. you might try cleaning it with a cotton swab.

    its a safety thing. the machine gives an ignation source (spark), then it supplies fuel in hopes of ignation. it then checks for ignation with some sort of sensor. if it does not sense a flame, it stops fuel flow, its a three strikes and you are out. the out is to make someone go down and check the furnace, find the problem and then do a reset (little red button).

    the return air fan will not usually turn on until the fire box has heated up (on newer units anyway) this is to keep the furnace from blowing cold air until the furnace does heat up. sorry for spelling.
     
  4. Ross

    Ross Moderator Staff Member Supporter

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    So the "burner element" comes on meaning a nice row of blue flame, and then it flares into white flame??? While I agree its shutting off because the flame sensor is dirty or soot covered its also doing its job! The soot may be coming from the "flame" which shouldn't be there and from your description I'd guess you need a new burner.
     
  5. ChickenHound

    ChickenHound Well-Known Member

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    Location:
    IL
    Thanks so much for all your help! You all guessed correctly as to the problem...

    DH pulled it apart when he finally got home, and only one 'burner' was lighting. Apparently there was some soot and other 'ick' plugging the 'line' which carries gas to the other 2 'burners'. So the furnace kept shutting itself off since the other two wouldn't light.

    We have heat! Whoo Hoo!! :sing:
    Thanks again!