NDR - troubleshoot furnace problems

Rocky S

Rocky S

Member
Anyone know a good place to find a troubleshooting guide for a Trane XE90?

Furnace is 5 - 7 years old. Tried to run it tonight since the nights are getting cooler here in Kansas and it won't be long until we need it. The draft fan comes on and then the ignitor, but the gas valve isn't getting signal to open.

This unit has "self diagnosis" but the LED is just "flashing rapidly" which indicates that the thermostat is calling for heat.


I'm SO CONFUSED!!!!!!!!!!!!!
 
Don't know about that particular problem. I have two high efficiency furnaces that have glow plug igniters and have had to replace those several times. My Mom's furnace had to have the control box replaced last winter. It was a Lennox and I didn't have a clue about it...called the guy that put it in and he had it going in 20 minutes. Is your gas valve on?
 
Might be that the gas valve is stuck and a slight tap or two might free it up.
Another possibility that I've come up against with other furnaces is a bad thermal couple.
I'm not a furnace expert but I have stayed at a Holiday Inn Express in the past. ;) I was once a "lower income housing technician" and owned a bunch of houses in Detroit and the thermal couple (or is it thermocouple) was the problem with furnaces as well as water heaters.
Lou
 
Lou, these new fangled (about the last 25 yrs) furnaces don't have pilot lights....it's all puter driven switches and valves. Probably a mother board fault.
 
Probably about as useless as anything, but on ours (not a trane) we had an ignitor fail with the same results. And of course it happend when it was freakin cold out. Lucky for backup heat sources. I keep a spare ignitor around just in case now.
 
Rocky

Those decoders are pretty good, usually points out the problem, until the board goes bad, they you get irratic behavior and codes. Try resetting it a couple of times (turn of the main power, likely 110 volt, coming into the unit for 30 seconds or more) See if you get the same flasing code again. If you get a couple of different codes, that is an indicator that it is a bad board.

Good luck,
Chuck
 
Hmmmmmmm, actually, I just missed the coal thingy.....by merely one ice age. ;)
We didn't even have coal available back when I was growing up. We had to age and crush plants by hand to MAKE our own coal.....barehanded and barefooted. Man, I tell ya........it was tough.
Lou
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Lou did you have to shovel coal into those furnaces?
 
if it doesnt see the ignitor sparks it will not start some have a fire eye of sorts on it ,it tells the gas valve to open,sometimes crap gets on the eye and even tho good spark no start..its a safety so one does not blow ones self up
 
Got it to work: went through and jiggled all the wires that connect to the control board to see if they were loose and sure enough I found one.

Wife thinks I'm a hero. Maybe I should fix more stuff around the house..........................nah!
 
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