Trane XV80 hard lockout, 2 flashes, Can't be reset


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Old 01-10-13, 12:50 PM
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Angry Trane XV80 hard lockout, 2 flashes, Can't be reset

I can't reset the lockout. Gas valve does not open or click, Igniter does not light or receive power. Nothing happens when thermostat turned to heat. Circuit board has power & air-conditioning mode works implying thermostat OK. Nat gas furnace will not do anything. Igniter measures 70 ohms. The only way I can get diagnostic Red LED light to reset is to switch to AC then go back to heat where I get an immediate lockout without anything happening in the furnace sequence of lighting off. Looks to me like the circuit board is bad but I don't know if something else could be causing an immediate lockout with inability to reset.
Can anyone help me? I am stumped at this point and don't want to buy a circuit board without some verification. Thanks for anyone's help. Mickey
 
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Old 01-10-13, 04:39 PM
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I agree that it sounds like a circuit board problem. So far as I'm aware, shutting off the power and turning it back on should cause the furnace to reset.


But wait and get some additional opinions on this oddball symptom would be my suggestion.
 
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Old 01-10-13, 05:06 PM
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a 2 flash with absolutely no operation from the furnace does seem to indicate a control board failure.
 
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Old 01-10-13, 05:37 PM
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Thanks guys! The Thermostat is applying power. Both limit switches OK. The 2 microswitches attached to the air pressure lines are OK except one stays closed & one open sensing fan air I guess. Zero voltage read between green & white 120VAC input wires. I don't know what else to check. The darn circuit board will not reset and LED gives 2 flashes for lockout, and it means TOTAL LOCKOUT. Could you guys give me an idea how to go about buying a board to try? The only place near me just about doubles the price unless you are a HVAC company. Do I need to replace the part of the board that says "White-Rodgers" on it or just the green circuit board. Thanks again for helping.
 
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Old 01-10-13, 07:08 PM
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Please post model number of furnace.
 
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Old 01-11-13, 11:07 AM
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Trane XV80 Hard Lockout,2flashes, unable to reset.

Checked for thermostat voltage to Red & W1, checked limit switches, checked for 0 volts between green & white line input voltage, checked for loose connections. Red LED continues to flash 2 times after power recycled for reset.
Gas valve & igniter receive no power. I don't know what else to check. Does anyone have any more ideas to prove circuit board is bad?


My Trane furnace model is XV80, model # TUD100R9V5H6. If circuit board, do I replace the white box labeled "White-Rodgers, Model 50A51-507" or just the small green circuit board labeled "American Standard 21C148501P01?


I appreciate any more help you could give me including where to buy the board.
Thanks! Mickey
 
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Old 01-11-13, 01:02 PM
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Yes, replace the White Rogers ignition control.
 
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Old 01-11-13, 03:53 PM
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Here is what you need: [TABLE]
[TR="class: DataTableResults"]
[TH]Part Item Number [/TH]
[TD="colspan: 3"] KIT09370 [/TD]
[/TR]
[TR="class: DataTableResults"]
[TH] Description [/TH]
[TD="colspan: 3"] KIT; RETROFIT KIT FOR CNT02223 , INCL: IGNITOR, IFC PLATFORM, DOOR SWITCH, BRACKET FOR DOOR SWITCH, SCREW, WIRING, HARNESS ADAPTER, TRANSFORMER AND IFC 2-STAGE, V.S. SiNi
[/TD]
[/TR]
[/TABLE]

[TABLE]
[TR="class: DataTableResults"]
[/TR]
[TR="class: DataTableResults"]
[TH]External Part Note
[/TH]
[TD="colspan: 3"] INCLUDES: SiNi IGNITOR - IGN00152, AND INTEGRATED FURNACE CONTROL - CNT03078. [/TD]
[/TR]
[TR="class: DataTableResults"]
[TH]
[/TH]
[/TR]
[/TABLE]
 
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Old 01-12-13, 12:43 PM
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Looks like a lot of parts there, HVAC Tech. What's the advantage of ordering that kit?
 
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Old 01-12-13, 01:53 PM
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Updating to current standards. There is a reason for the upgrade from the manufacturer.
 
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Old 01-12-13, 03:46 PM
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Is that a different kind of ignitor that might use a different voltage?
 
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Old 01-12-13, 09:11 PM
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Trane XV80 Hard Lockout,2flashes, unable to reset.

A repairman told me there are 5 interlocks like limit switches that keep the system shut down or from the start sequence. I only know of the 2 limit switches. Can anyone tell me what the other 3 are?

Could the igniter out of limits be one? Could the 2 air pressure switches be a part of it?

Any help would be appreciated. Thanks! Mickey
 
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Old 01-12-13, 09:16 PM
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Trane XV80 Hard Lockout,2flashes, unable to reset.

Thanks for the info on Kit. Do I really need to pay $459 + shipping? Wow!
Would ebay be a good place to buy it?
 
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Old 01-13-13, 12:08 AM
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Some Trane units require that you cycle power twice in 30 seconds.
This may apply to your furnace (though I can't find an XV80 manual).
I would try this before spending any money...

7. RESET AFTER LOCKOUT
When the integrated control module has shut the
system down and gone into lockout, the system
must be manually reset before the unit will restart.
To reset, turn the system power off, then on, then
off and then on again within 30 seconds. This may
be done at the unit’s power source or at the thermostat.
The system will not reset unless the procedure
off-on-off-on is completed within 30 seconds.
 
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Old 01-13-13, 10:27 AM
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I was told there are several types of ignitors all measuring different impedances such as 15 to 70 ohms.
 
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Old 01-13-13, 10:33 AM
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Good word Houston204 on the proper reset procedure that I will try! Do you know if BOTH fan air pressure bellows safety switches are normally closed? With furnace shut down, one is open & one is closed. I guess they are considered safety switches. They both have the same type of micro switch attached.
 
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Old 01-13-13, 11:15 AM
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If you are referring to 2 separate pressure switches connected to the furnace, they are normally open.

If you are referring to one pressure switch with a C, NO and a NC terminal, one is normally open and one is normally closed.

It is strange that some Trane furnaces use 2 flashes for pressure switch lockout and some use 2 flashes for hard lockout. Did you get your LED definition from your furnace panel or the internet?
 
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Old 01-13-13, 12:08 PM
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http://www.butcherdistributors.com/I...ior/tud_rv.pdf

Take a look at page 23 Note 6..

6. RESET AFTER LOCKOUT
When the integrated control module has shut the system
down and gone into lockout, the system must be manually
reset before the unit will restart. To reset, turn the
system power off, then on, then off and then on again
within 30 seconds. This may be done at the unit’s power
source or at the thermostat. The system will not reset
unless the procedure off-on-off-on is completed within
30 seconds.
 
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Old 01-13-13, 01:22 PM
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Houston, I'm a Trane dealer. I have never had to reset like that, but it does say it. Page 24. Shows the flash code legend. It is system lockout and not a pressure switch code.
 
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Old 01-13-13, 01:49 PM
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I've been working on Trane units for 2 decades and I learned this information while posting on these sites as well. I've learned a lot reading manuals for posters on these sites.

Trane has some great continued education courses here in Houston. David and Angelo make the classes educational and entertaining.

The sequence of events should be observed after resetting it to find out why it is locking out.
 
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Old 01-13-13, 07:08 PM
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The White rodgers Model 50A51-507 states on the label that 2 flashes means, SYSTEM LOCKOUT, NO FLAME CHECK POLARITY.

Does check polarity mean check between green & white 120VAC input wires to make sure chassis is grounded. I checked & read 0 volts.
 
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Old 01-13-13, 07:15 PM
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did you get it to reset? Verify polarity means verify 120V between hot and neutral and between hot and ground.
 
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Old 01-13-13, 07:25 PM
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Thanks Houston! The main problem is that I can't reset it to observe the sequence of events. It is a HARD LOCKOUT. When I go to Air Conditioning mode everything works and I get a reset. Upon going back to Heat, Draft motor runs for about 3 seconds followed by an immediate lock out lockout & shutdown with 2 flashes before gas valve or ignitor can work. After that, system stays locked out and can't be reset.
 
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Old 01-13-13, 07:34 PM
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Can't get reset! I verified 120VAC like you described and also checked for proper ground, ie: 0 volts between green & white 120vac input. I have run out of ideas.

The fan air sensing bellows with the 2 identical micro switches don't seem right to me. One is closed and one is open. When the air pressure goes up due to fan turn on, I guess the off switch turns on and the on switch turns off at a certain level of pressure. Could these 2 switches cause a lock out?
 
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Old 01-13-13, 07:54 PM
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The pressure switches should be open until the inducer runs. If they are closed before the inducer gets a demand you should get a pressure switch error code 3.
You can unplug the wire to the pressure switch in question and do whatever it is that you do to get the inducer to run again. (this sounds like you are able to reset it)

Did you measure for less than 3 VAC between neutral and 24VAC common?

I would also try unplugging the flame sensor wire and giving the furnace a heating demand after resetting power twice. The timing would point to the pressure switch or here.
 
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Old 01-13-13, 10:11 PM
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Thanks again Houston! I am only able to reset it by going to COOL & then back to HEAT, in which case inducer fan runs for about 3 seconds, with no igniter or gas valve on, followed by lockout with 2 flashes. Normal reset procedure does not work.

I will check for less than 3VAC between neutral & 24VAC common tomorrow. I assume neutral is the white wire feeding 120VAC to the unit. How about the Green wire to 24VAC common? Is that important?

Houston, it would seem to me that the circuit board will not reset the normal way because something serious is faulty as important as a safety switch. If I can fix that component the circuit board will then reset. Whatever is keeping it from reseting is keeping it from the start sequence. Does this sound right? Can a faulty Flame Sensor prevent a reset?
 
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Old 01-13-13, 10:35 PM
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Your circuit board sends ~ 90 volts to the flame sensor. If it is damaged or shorted something like this could happen ( though I would expect a flame sensor error).

Unplugging the flame sensor would delay the lockout until after ignition occurs if the problem is only a faulty or shorted flame sensor.
 
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Old 01-14-13, 08:59 PM
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Thanks Houston. I will try that tomorrow and hopefully I can get your opinion again. (repairing broken toilet today) Appreciate all your hlep. Mickey
 
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Old 01-14-13, 09:11 PM
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Unplugging the flame sensor probably will not require any tools once you get into the panel but I usually use a 1/4 inch nutdriver to remove and clean the flame sensor (with steel wool).



 
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Old 01-16-13, 03:23 PM
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Trane XV80 Hard Lockout,2flashes, unable to reset.

With a lockout, should't the small fan motor be locked out when r-w is jumped?


In any case jumping it will not make it work. However it will work for 5 seconds when coming from cool to heat, followed by a lockout with 2 flashes.


I checked all voltages and they are normal. It seems like something is locking the circuit board out before any start sequence is initiated like the board is sensing something wrong, open, or not in tolerance.


Could the ignitor measuring 70 ohms or flame sensor be out of limits enough to cause a lockout? Thanks again for your help.
 
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Old 01-16-13, 05:22 PM
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The flame sensor may be shorted to ground.
Unplugging the flame sensor would be a method of checking this.
 
 

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