A few furnace questions
I have a Trane XE80 gas furnace that has been acting similar to others I’ve read about. Everything is working properly in sequence until it gets to energizing the gas valve and delivering gas to the burners. Then after it tries 3 more times, the ignition board displays the 4 flash “Thermal Protection Device Open” signal. When it does finally fire up, after “jiggling” some wires on the board, it will run normal until it decides to mess up again on another start-up sequence.
Since the diagnostic advised that the board was not the problem:
“Open Thermal Protection Device” If the primary (high) limit, auxiliary limit, or rollout limit control opens, the gas valve is de-energized. Both the induced draft blower motor and air circulating motor are energized on low heat speed. The diagnostic light code for this is four short flashes followed by a longer pause. If the primary or auxiliary limit is open, the probable cause is either: low conditioned air flow due to dirty filter or high resistance in duct work, faulty limit, faulty blower, or blower speed set too low. The primary limit will automatically reset, while the auxiliary limit control must be manually reset.
I checked for an internal filter and none were located. I also could not locate any reset buttons on the limit controls (fig.1, fig.2 & fig.3). Even though the diagnostic says it’s not the board, the back of it looks like this (fig.4). When I “jiggle” some of the wires to the board it will cause lots of clicking in the relay and the gas valve will energize and it will either fire up or attempt to. I’ve checked contacts & connecters on the board and they’re clean & tight. I have to leave the front panel off the furnace and have the board lying horizontal on a shelf like shown in the pic or the furnace won’t even attempt to work.
I’m pretty convinced the board is bad but, could it be a combination of things? Also, my kids messed with the numbered dial under the thermostat cover (fig.5). I don’t know what it does, what it should be set at or if it’s adding to the problem. Any advice is appreciated, thanks.
Sorry, this is not a DIY site!
The issues you are having with your equipment are not homeowner repairable.
It's time to call a service contractor to evaluate what is wrong and have him properly repair your equipment.
The thing your kid messed was is the heat anticipator, when you have your equipment serviced by a pro he will readjust it for you.
FWIW, maybe it's time to upgrade that stat anyway.............
Forum Rules are in my Signature Line, check them out!
Thanks for the response.
Say....I wanted to save some money and order a replacement board. Do you think that could solve the problem? Does the back of that board look bad to you? It looks like it's been burnt up to me. Is it possible for the LED diagnostic to give a false reading and the board be bad?
Here is my advice...........and I am not saying this because I am trying to convince you into calling someone.
Saving money these days is extremely important, especially if you are in Michigan because no one has any money up here.
However, if you replace the board based on the way it looks, and you spend more than a few bucks buying one, and it does not work, and ya gotta call someone out then to properly fix it, have you saved any money?
Call a contractor, don't be cheap, pay the freight and get it fixed right.
Heybob: You gotta love it.
You address the DIY issues with this person.
They proceed to make a failed attempt to 'disguise' their question.
For example: "Well, if I was to change the board, do you think that would fix it?"
My philosophy about DIY on this site is yeah, the one guy you are communicating with may be able to turn a screw, BUT the other 1000 that are viewing the thread over his shoulder may only accomplish major damage!
Way to nip it in the bud, Bud.
all the best, Irish
Everyone has a purpose in life..........even if it's to be a bad example.
Seek first to understand, before seeking to be understood.
Ok Mr. Moderator, then what are you going to discuss on this forum? How much you can charge a customer or what parts to say need replaced when they're actually fine? Your in the same category as an auto mechanic. I don't need 5 years apprenticeship or schooling to switch out a circuit board. You can still help a person out, DIY site or not, without sticking to your union ethics of making money. I'm not paying some jerk-off whatever he wants to charge me to tell me what I can find out for myself. Thanks to the Internet I can find out anything I need to know about HVAC along with order any part I need. Your a dying breed, a dinosaur, destined toward the same fate as the music industry & libraries. I think I'll spread all the "DYI" info I can find all over the net. Time to look for new job Irish!
And you are who again?....lmao...What the.......
Originally Posted by Bradburn911
I am here to make money for me and the company, I only guarantee one of 'em.
Well, I can tell your momma raised you right just from that post.
Originally Posted by Bradburn911
And by the way, if your "wiggling wires" makes your furnace work, do you actually think the board is the only issues it has?
Do not argue with an idiot. He will drag you down to his level and beat you with experience.
Yep, considering solder points are broke on the board and the "wiggling" is going on next to the fried piece of junk and know where else. It doesn't take an Hvac "Pro" to figure that out. If you came out you would be charging me for crap I don't even need. Sorry for the bunk career. Next time choose wisely.
Exactly what I said! Your signature says it all. Screw the customer your there to make money! Thief!
Originally Posted by patg88
OK, The original poster has decided to fix his own furnace, ignore our advice and inform us that we are all theives.
Not quite sure what he does, nor do I care, but he is obviously too obtuse to follow the rules of this site.
Oh yea, the rules:
2. Do-It-Yourselfers - not here.
This site is for industry professionals and folks seeking HVAC/R advice and knowledge. Please do not ask for step by step instructions on purchasing, installing or repairing your own HVAC equipment, that is our job and our livelihood. We are generous, but not to a fault.
Questions of this type will not be answered and may be deleted.