Author Topic: Trane Furnace / White Rodgers Controller  (Read 12592 times)

Offline coopsterj

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Re: Trane Furnace / White Rodgers Controller
« Reply #15 on: October 20, 2010, 09:58:42 PM »
Do you have an altenate method for me sending you photos.  Each photo I have is approx 1.84 MB, and is too large to send as an attachment (as the max. attachment allowed is 500 KB).  I whittled the photos down to 5, but that makes the file 9.08 MB.  Again, I truly appreciate your help and patience with this project.

Offline coopsterj

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Re: Trane Furnace / White Rodgers Controller
« Reply #16 on: October 21, 2010, 08:31:15 PM »
It's always great to remember you can pare down the resolution of a digital camera!  Too many 16 hour days!  Attached are three photos; showing the burner assembly and the ingitor cables disengaged, my multimeter, when set at its lowest setting of 200, displaying the reading when checking the ignitor, and the unit as a whole.  I can provide more photos, if it helps.  Look forward to your reply.

Offline coopsterj

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Re: Trane Furnace / White Rodgers Controller
« Reply #17 on: October 21, 2010, 08:34:19 PM »
OK second try to get two more photos to you.

Offline coopsterj

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Re: Trane Furnace / White Rodgers Controller
« Reply #18 on: October 21, 2010, 08:35:18 PM »
And the third try is the charm!

Offline JWWebster

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Re: Trane Furnace / White Rodgers Controller
« Reply #19 on: October 22, 2010, 03:14:18 PM »
Looks like the ignitor is ok 93 ohms showing. Check that fuse with the yellow wires connecting to it. If it is bad then replace it and then remove them burners and wire brush them and check for splits or anything else that would cause rollout or overheating like cobwebs in the flues or bird nests etc.
« Last Edit: October 22, 2010, 03:24:42 PM by JWWebster »
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Offline Icehouse

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Re: Trane Furnace / White Rodgers Controller
« Reply #20 on: October 22, 2010, 04:15:28 PM »
Problem: Your furnace will not ignite the gas to produce heat for your home. When a furnace has a bad ignitor what I see most of the time is the following sequence of operation:
 

1. Thermostat calls for heat.
2. Draft inducer motor starts.
3. Pressure switch attached by a small plastic or rubber tube senses the negative pressure  produced by the draft inducer and closes.
4. Draft inducer runs for 30 seconds to a minute before you hear a gas hissing sound. The ignitor did not glow, the flame sensor (a small metal probe about 1/8" in diameter, with a white porcelain base) does not sense the flame, so after 8 to 10 seconds the hissing sounds stops with no ignition of gas to heat your home. Your furnace shuts down and goes into a lock out condition until you turn your power switch back off and on again. Then the sequence starts all over again with no ignition of the gas.
Solution: You probably need to purchase and install a new ignitor. I would suggest that you inspect your ignitor closely for cracks. Make sure you do not touch the ignitor with your bare hands. If you do not visually see a crack, then you could have a furnace control board problem or a limit, rollout switch problem. The furnace's control board might not be supplying the voltage to the ignitor.  If your furnace lights and the gas stays on for 8 to 10 seconds, then shuts right back off, then you need to clean your flame sensor with light sand paper or steel wool. You might need a new flame sensor, but most of the time they can be cleaned an will work well after cleaning.
NATE, NCCER, PHCC,HVAC Certified Instructor
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a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline coopsterj

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Re: Trane Furnace / White Rodgers Controller
« Reply #21 on: October 24, 2010, 08:14:24 AM »
Great Information- JWWebster and Icehouse...albeit with a couple of questions.  I was under the impression that when my multi-meter was zeroed out, and then inserting the probes into the unit being tested, ideally the meter should read back to zero, to show it is operational, instead of reading the 93 ohms.

Icehouse- It is exactly as you decsribed regarding the sequence of furnace operation. However, there is never an ignition.  The ignitor does not appear to have any cracks.  (What is the reason to not touch it with bare hands?)

Before I spend $30-$40 on an ignitor, (and find out it wasn't the problem), is there any way to test the control board, or what I call the controller?  All replys are very much appreciated.  This is a photo of my current controller.

Offline Icehouse

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Re: Trane Furnace / White Rodgers Controller
« Reply #22 on: October 24, 2010, 09:57:55 AM »
 O0  Not touching the igniter because the oils from your body will cause it to short.
This happened on the old glass heaters used to defrost refrigerators.
Had a pair of "Lambs Wool" gloves just for this reason.
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
a tragedy has happen to me : http://web.me.com/zenzoidman/Bobice/

Offline JWWebster

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Re: Trane Furnace / White Rodgers Controller
« Reply #23 on: October 24, 2010, 11:31:00 AM »
Skin oils cause premature failure plus these silicone carbide ignitor are very fragile as well. Just banging on the furnace can break it. I do not know what the resistance value of a furnace ignitor is but they do have resistance if they are good. If you could not get any reading then the ignitor is bad. I have a test cord with a male plug on it. I power em up with a direct 120 volts to check em.
May the hinges of our friendship
        never grow rusty.

About the icons: The beer is tip link, if a tech saves ya some money buy em a 6 pack. The small green square=personal message. The green dot is a link to my web page on appliance repair and other general BS I love to post. The letter sends me email.
I love fan letters! LOL

Offline coopsterj

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Re: Trane Furnace / White Rodgers Controller
« Reply #24 on: November 03, 2010, 11:12:59 PM »
Thanks for all the help and assistance.  I replaced the ignitor, and unfortunately that wasn't the problem.  Turns out it was the control board, (of course one of the more expensive fixes).  One bright spot, I Manage a very popular restaurant, and was able to trade a couple of dinners for the $40 ignitor.  Damned if I could get the parts warehouse to do a full or partial trade on the $193 control board.  At least we're back up and running.  Again, thanks for all your help.

 

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