FURNACE RUNS, BUT NO HEAT!! grrrrrrr.


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Old 03-10-12, 01:11 AM
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FURNACE RUNS, BUT NO HEAT!! grrrrrrr.

I have a TRANE XL90. This afternoon I noticed it was very cold in the house (59 degrees) and I heard the furnace fan running. Turns out, the blower (or initial fan) runs but the heat does not come on and blow hot air. help!

 
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Old 03-10-12, 04:37 AM
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there is a small window in the blower door. What flash code do you see? On the back of one of the doors (burner or blower) will be a legend describing what the flash code means. Post that info here.
 
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Old 03-10-12, 03:25 PM
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pardon my ignorance but i dont even know where the blower door is. i do know what the blower door switch is though.
 
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Old 03-10-12, 04:19 PM
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The blower door is the door without louvers.
 
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Old 03-10-12, 07:19 PM
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the unit has 2 panels. the top panel is long and has louvers. the bottom is shorter and flat (no louvers).
 
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Old 03-10-12, 08:13 PM
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UPDATE: here are several pics. I am a novice, but would appreciate any help. Also, there is power and the blower fan starts everytime when I raise thermostat above room temp. Also I hear the clicking (several times) for the ignitor, so my guess is that the ignition device is not triggering a flame? to the gas. and yes I smell i tiny bit of gas when it turns on and runs and clicks with no heat produced. help!













 
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Old 03-11-12, 07:17 AM
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You dont have a led flash code on that old XL90. Your furnace is 25 years old! Before you sink much of any money into it you should have it examined by a professional.

Now, onto your problem... Shut the thermostat off and then turn it back on to heating.... sit in front of the furnace and in detail describe the sequence of events that happens. You may need someone else to turn on the thermostat while you are in front of the furnace. You may have to do this a couple of times to be able to describe the sequence in detail. Post back here with your results.
 
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Old 03-17-12, 07:52 PM
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If it doesn't blow hot air, you might be hearing just the ventor motor.

Do you see the the metal box above the gas valve? Pull the peg out and see if the fan comes on. (if it does, the blower's circuit is okay)

Your filter is completely plugged - change it.
 
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Old 03-18-12, 04:57 AM
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Do you see the the metal box above the gas valve? Pull the peg out and see if the fan comes on. (if it does, the blower's circuit is okay)
You would push the white peg IN to turn the blower on and pull it out to return it to auto function.

@muggle - good catch on the spacegueard air filter being plugged, I never even saw that!
 
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Old 03-18-12, 07:49 PM
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I stand corrected.




. .
 
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Old 03-19-12, 03:58 PM
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Could it be going off on limit with the filter that dirty?

There's a condensate leak (where the corregated hose joins the CPVC?) which also needs attention.
 
 

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