1. Attention: We have put together a thread with tips and a tutorial video to help with using the new software. Please take a moment to check out the thread here: Trapshooters.com Tutorial & Help Video.
    Dismiss Notice

Gas Furnace Question

Discussion in 'Off Topic Threads' started by kenf, Jan 15, 2013.

Thread Status:
Not open for further replies.
  1. kenf

    kenf Active Member

    Joined:
    Jan 29, 1998
    Messages:
    1,016
    I have a question for those familiar with natural gas furnaces. My question is if I have a bad thermostat, or if I have an issue with the furnace?

    The house I recently moved into had a new high efficiency Ducane furnace installed in 9/2011. Recently, the furnace would not come on despite a drop in temperature observed at the thermostat. The thermostat is a digital White Rodgers that is not programmable. I did realize that if you turned the thermostat off for a few seconds, the furnace would come on and run normally until reaching the set temperature and then shut off.

    Last night, something gave up. When turning the thermostat on and off, the furnace would just start the initial fan for a few seconds, the immediately shut off. I did pull the thermostat off and run a jumper wire across and the furnace would come on and run for a few minutes, but then shut off again. The hotwire and gas didn't come on to make heat- so I don't believe those are an issue, but I'm not sure about the gas flow solenoid.

    The furnace also has a LED indicator that will flash codes to indicate certain malfunctions, but it was constantly on, indicating that the furnace was okay.

    The furnace was installed under the weatherization program, and no one left any contact information, so I'm not sure if a service call/parts are under warranty or not.
     
  2. slayer

    slayer Well-Known Member

    Joined:
    Nov 16, 2006
    Messages:
    2,929
    Location:
    beautiful northern michigan
    The new furnaces won't run with a dirty filter. You may want to check that out. Bill
     
  3. kenf

    kenf Active Member

    Joined:
    Jan 29, 1998
    Messages:
    1,016
    I pulled the filter and it wasn't plugged, but it is about due for a change.
     
  4. ScottEslick

    ScottEslick Member

    Joined:
    Aug 5, 2009
    Messages:
    351
    Location:
    Waynesboro, PA
    Sounds like the furnace was locking out on something and when you turned it off it reset its self to try again, could be any number of things, dirty flame sensor, board failure, etc.

    Might be better off having a service call to get it corrected

    Scott
     
  5. 548

    548 Guest

    Remove the flame sensor and clean it with a high grit sand paper. Common problem, I have to clean or replace my flame sensor every winter. That is an easy fix if that is your problem, if it doesn't fix the issue then call a service man.
     
  6. scooterbum

    scooterbum Active Member

    Joined:
    Apr 3, 2009
    Messages:
    1,193
    Are the batteries good, in the thermostat?

    I would first check the combustion air flow pressure switch and it's components. No kinked or leaky or plugged hoses, elec connections good, continuity of switch.
     
  7. kenf

    kenf Active Member

    Joined:
    Jan 29, 1998
    Messages:
    1,016
    Thermostat batteries are good, thanks for the suggestions, I'll check on them.
     
  8. HSLDS

    HSLDS Well-Known Member

    Joined:
    Nov 2, 2006
    Messages:
    6,349
    Location:
    S-E PA
    I think 548 nails it.

    Old furnaces had a pilot light that burned constantly - then a thermo couple that felt that heat and told the valve body it was OK to release the full gas flow when heat was called for. Then there was the flame sensor that said the main flame had gone on.

    Rather simple system and well proved over time.

    The 'high efficiency' units have so many variables that they NEED the code reader you mentioned.

    IF the flame sensor is bad it will show an open circuit at all times - essentially telling the furnace that no flame is present, even when there is. This is not an error code, merely a situation issue (as you said it did work when you re-set the thermostat) - could mean there is no gas flow, that wind has blown the flame out, etc. It is a normal part of the operation so it would not throw an error code.

    You can check the flame sensor yourself: http://www.wikihow.com/Test-a-Flame-Sensor

    Start at line 6...
     
  9. Patrick Haskins

    Patrick Haskins Member

    Joined:
    Jan 29, 1998
    Messages:
    557
    It may also be the ignitor. It is a common problem with new furnaces.
    Pat
     
  10. Advocate33

    Advocate33 TS Member

    Joined:
    Mar 25, 2012
    Messages:
    24
    I can tell you what happened to me. Check the rubber tubing to see if it is perished or leaking air. The tubing goes from the draft inducer fan to a vacuum switch. If it is loose or perished, no vacuum hence the switch will not work. The furnace will start. The draft inducer fan will run for awhile and then the furnace will just stop. A 10 cent rubber tube cost me $100 for a service call.
     
  11. WesleyB

    WesleyB Well-Known Member

    Joined:
    Aug 19, 2007
    Messages:
    1,472
    Doesnt both lights need to flash together slow for normal operation? I had to unplug the main power to furnace to reset the circut board because my lights were solid on and not flashing,, then one would be solid and the other flashing fast. When i unplugged the power for a bit then plug back in it worked fine for awhile.. but later that night it quit again.. I then cleaned all my sensor blade connectors and valve connectors... now all works fine
     
  12. kenf

    kenf Active Member

    Joined:
    Jan 29, 1998
    Messages:
    1,016
    Well,

    I got the problem fixed. The issue was a bad combustion air pressure switch. Fortunately, I was able to remove and install the new one myself- just two wires and air lines running in and out of it.
     
  13. scooterbum

    scooterbum Active Member

    Joined:
    Apr 3, 2009
    Messages:
    1,193
Thread Status:
Not open for further replies.