# TRANE XE80 - 2 red flashes - intermittant



## Thomasv (Jan 23, 2010)

Hi everyone,
I am hoping someone can shed some light on an intermittant issue I have bene having with my trane xe80.

Issue: 
Sometimes the unit will kick on, ignite and work perfectly! Sometimes it wont even make it past 10 seconds before the flame extinguishes and it tries two more times before it locks out. For the most part it fails more than it works...id say fails 95% percent of the time...if it does manage to stay on it will bring my house up to 70 deg. which is what i set it to stay all the time. If its at 70 and falls by 3 degress it is supposed to kick back on...well it doesnt, it starts failing and locks out with a code of 2 red flashes.

So I had this problem last year and a flame sensor was replaced...it seemed to fix the issue until now. So i bought another flame sensor and installed it..didnt work...

I called out a professional who did a bunch of ohm meter testing and said everything seemed fine...he "adjusted" my flame sensor and said he fixed it...wrong. 

Since i knew the guy who came out he has been tryin to help me save money by coaching me through it..he only charged me for 1 hr of service but has been here a total of 3. He seems to think its my pc board even tho im not getting a internal failure. When the flame is on and starts to fail you here a crapload of clicking noises...like a relay going crazy....

To make a long story short i started replacin the cheaper parts...

what ive replaced so far, forgive me if my terminology isnt correct, but im trying. 
1. Flame sensor
2. Igniter
3. the two safety peices (at top and bot near the flame sensor and igniter)
4. P15 (hi-low) thingy to the right of the main gas actuator
5. white rodgers board - (got off ebay...waiting to get another one from the seller to see if he sent me a bad one) 

* i found a wire that was hanging from the bundle of main wires and it was touching the hot surface of the fan that blows out the hot air...it went to the high side of the p15 part...so i cut the wire and spliced it back in...the unit came on and was working great but later on failed in the exact same fashion as before. 

I also bought me a white rodgers board thinking that my pc board may in fact be the issue. Installed that one and when i plugged it in i got 5 flashing red lights...telling me flame sensed with gas valve off....well i ordered that part of an ebayer so i will be returning it to try my luck with another from him. The only difference between that pc board and my original was the 3 tabs to 4 tabs...my original has 3 config tabs that are all in the on position....the new one has 4 tabs..but they are both the exact same part number and everything. Anyway....so i install my original pc board back in and the thing kicks on great...im thinking well maybe a loose wire...so i sit back and watch my house get up to temp...kicks off....cools down...and than tries to reach temp again...fails...sigh 

Ok now....i said before i changed igniters...ive noticed something wierd with the igniters...the tech that came to my house installed one for free...i noticed that when it tried to ignite it wouldnt always just glow orange nicely...sometimes it would be really bright white..like its arcing or something...

well the other day i tried to do more troubleshooting and noticed the igniter wasnt even attempting to come on anymore...so my tech guy put a new one on and boom...ignition....so we have put on 2 brand new igniters and still have the problem with it working consistantly...

just yesterday i go up and turn on the unit and its working great....came home...not working...today i go up and plug it in again and now im having a dead igniter problem yet again...i have another igniter in a box ready to go but maybe there is something in the system blowing out my igniters? 

so i let the system fail again to get the code and its right back to the 2 flashing lights.... (no flame) check line polarity....

sorry for writing a novel...any help would be much appreciated

im ready to kick this ing thing down the street


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## Bouwwhuis2000 (Jan 23, 2010)

I know how you feel with the intermittent furnace problem.
I have experienced the same frustration.

If you have a meter with a 50 micro-amp scale you can confirm if the flame sensor is delivering 1-2 uA of current with flame. If the sensor has just a single wire, you can hook up the meter in series with the feeder wire. Red meter lead to the sensor, black to the wire. No flame = no current. 
If the board does not see the current within a short time, it will turn the gas off.

I'm no expert but I am learning.


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## Tator1076 (Dec 22, 2009)

Did you check limit switch? Note replacing the flame sensor is some what wrong. You just need to clean it every year with a dollar bill. I only change them when its never been clean and the furnace is over 6 years old.


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## H. Phillips (Jan 5, 2010)

Is the gas valve clicking? Did you tap the pressure switch to see if it would make the flame drop out for an instant? I had a similar problem and replacing the pressure switch did the trick. The Trane rep said they hardly ever break and suggested I replace the gas valve, but breethere put me on the right track.


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## Thomasv (Jan 23, 2010)

Bouwwhuis2000 - I will test that later on tonight to see what the meter reads - I know that if i touch the lead and ground myself out it kicks on the blower motor. 

Tator1076 - where is this limit switch? are you referring to the HI and low? 145-40 or 45 or whatever... the texas instrument labeled P15? With 2 wires going into it? if so yes. If you're referring to something else the answer is likely no. 

H. Phillips - Yes, the gas valve clicks. In fact, when it fails it starts clicking a bunch. I too suspected the pressure switch may be failing, that or it could simply be clogged. I want to replace it but cannot find anyone who will sell it to me. When I get home I will tap on it to see what it does.


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## Houston204 (Oct 18, 2009)

Turn off power to your furnace and remove and clean the control board connections to the furnace body (ground). Dirt can cause a faulty connection creating a flame sensor lockout. 
Also verify that the field installed ground wire connection is clean and making agood connection.

If you reset power and watch the furnace untill lockout occurs, do any other error codes appear before your 2 flashes?


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## kennzz05 (Nov 11, 2008)

i second the pressure switch idea once it pulls in you could jump it to see if the flames stay on. or attach your meter to it with alligator clips while leaving thefurnace wireing in place and see if its dropping out


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## beenthere (Oct 11, 2008)

If you hear the gas valve clicking when it doesn't light. Then its probably not a pressure switch problem.


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## Grampa Bud (Apr 6, 2009)

ThomasV, Pay close attention to what Houston204 has said. The public in general has been duped into thinking if something doesn't work 
then you have to replace a part, but it doesn't work that way any more particularly with all the hi-tech electronics in everything. When I 
first read your thread, the very first thing that came to mind was "Did you check your system (in this case -furnace-) ground?" Not the 
120 & nuetral coming to the unit, but the ground continuity between PC boards, the furnace cabinet, valves, blowers, everything. New 
appliances directly from the manufacturer can have a ground continiuty problem just because of a little to much overspray when they paint 
the parts or maybe there is a sheet metal screw that didn't cut through the paint to bare metal. The fact that the furnace seems to work 
correctly for the first firing cycle BEFORE it displays some form of failure indicates to me that the problem is most likely heat related. Check 
around the firebox area, the ground lead(s) from the PC board to the cabinet, check the burners themselves to make sure every place metal 
touches metal it is clean and bright. 80 cents worth of sandcloth is worth more than a new furnace.


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## Thomasv (Jan 23, 2010)

wow this is all great information - i will have to check it out tonight for sure. 

I guess I should verify that the unit doesnt always fire up the first time and run through a full cycle. Just sometimes it actually works. Most of the time it comes on and gives me the ready for heat flashing light and just fails to lockout code. No other code comes on unless I remove and replace the pc board with another like board. I than do not ever get the ready for heat light and instead only get the 5 flashing red lights...


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## beenthere (Oct 11, 2008)

Was any electrical work done shortly before it started having trouble. 
Including any electrical work that may have been done late spring or summer.
Weather it had to do with your heating or cooling system is not important.


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## Thomasv (Jan 23, 2010)

not that i can remember. no electrical work has been done in anyway in some years. I put a jbox in to a hot water heater in 05 but that was it. Now that jbox has had some issues lately. I dont know why but it went through 2 fuses in 2 weeks. I had to keep flippin it off and flippin it back on becuase my hot water was not working. Thats the only noteable thing lately. I really should hard wire the tank in and remove the jbox since it does go to my breaker box in the house but its worked fine for 3+ yrs this way. 

*note - my igniter still will not glow orange. Its receiving power but the the gas just comes on for a second and shuts off....3 times lock out failure 2 red flashes.


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## beenthere (Oct 11, 2008)

A. That jbox trouble with blowing fuses could be causing troubles with the furnace. 

B. Are you sure your using the right voltage ignitors/HSI's(as in not using 24 volt ones on a 120 volt system).


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## Grampa Bud (Apr 6, 2009)

Beenthere; he would only do that once -using 24v for 120v. It would have a flashbulb effect. The older "glowplugs" on some gas fired water water heaters did glow orange, but the newer HSI's for furnaces seem to be much brighter -as in white hot. You might check your power .ie 120 vac and breakers -15-20 amps-. Do you have a lazy breaker? Are you sure that only the furnace is on the breaker as in a dedicated circuit ?? If your circuit is loaded to or over max and all the lights/appliances start simultainiously the overload condition could cause many strange things to happen. Pumps, furnaces, a/c compressers, Electric water heaters, microwaves, electric ranges, refrigerators, washer and dryers, and kitchen outlets among others should all be on dedicated circuits.


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## Ducknuts (Nov 13, 2014)

Sorry to drag up an old thread, but my furnace is having the exact same issue and i was wondering if you ever fixed it. Runs fine to start then after a few minutes it starts clicking like crazy then the flame shuts off and wont restart. Thanks for any info.


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