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gmay10

join:2012-01-08
Mount Joy, PA

Gas Furnace not always turning on

My gas furnace does not always turn. This has never happened during the summer, this only happens during the winter. I put in a new thermostat a month ago. We had a person clean the furnace last year and replace a cracked igniter. The thermostat is saying that the furnace is on but the furnace is not on. And I am pretty sure that the furnace is not trying to turn on at all

This was the problem last year when we called. The furnace would kick on and then turn off. They replaced the igniter and cleaned piece of wire that hangs down to detect if the actual furnace is on (a safety feature). I have done enough research to know that this is not occurring again.

If this occurs, I go downstairs and turn off the furnace using the switch. I wait a few seconds or minutes and then turn back on. Sometimes this works and sometimes this does not. Sometimes I have to take off the top panel cover. And then I have to take off the bottom control panel cover. I push in the button and see that that a red light is pulsing which the control panel says it should always be doing. We have replaced the filters a bunch thinking that could be the problem but I don't think it is. I just don't want to call someone and have then come out and say all is well with the world when it is not.



SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3

Once the furnace locks itself out (generally 3 to 6 attempts), the LED or LEDs will flash a code. There should be a legend on the inside of the blower compartment panel that will explain what the flashes mean.


gmay10

join:2012-01-08
Mount Joy, PA

It is flashing red like a pulse and it says that a pulse means that everything is OK. When I take the bottom panel off it basically turns itself off. Would that reset the "red flashing" button? I cannot see the red light when I take off the top of the panel.



SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3

On some furnaces, when the furnace is idle, the LED will flash at a "normal" rate. When the furnace is in the heating mode, the LED will flash at a "faster" rate. After 3 to 6 failed attempts, the furnace will lock out. Then, the LED will not flash at its normal rate. It will repeatedly flash a series of flashes that will correspond to the flash codes on the legend I mentioned.

Do not kill the power to the furnace or remove the blower panel. Doing so will reset the flash codes. Look through the site glass on the blower door and make a note of what flashes you are seeing. Then, you can remove the blower door to look at the legend to see what the flashes mean.


gmay10

join:2012-01-08
Mount Joy, PA

I have a GAMA model number GMP 100-4
I cannot for the life of me figure how I can look at the light without taking off the bottom panel which resets the light (From what you are saying). I have looked everywhere with the lights off and with lights on. And I have done this on multiple occasions. I have tried searching the internet as to where I can find a way to look at the blinking light prior to taking off that panel but I am dumbfounded



SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3

So, there is no site glass on the blower panel? Maybe your furnace doesn't have diagnostics. Is there a sticker (legend) on the inside of the blower panel showing diagnostic codes?


gmay10

join:2012-01-08
Mount Joy, PA
reply to gmay10

Yes, I actually just emailed the company about this tonight. I am telling ya. I have searched everywhere. Maybe I am completely off but there is no way I can see that blinking light without taking off the bottom panel. We moves into this house 6 years ago since this furnace was here before us. And for whatever reason the previous owners did not have the book. I have searched the internet tirelessly trying to figure out a way to see that light prior to taking off that bottom panel.


gmay10

join:2012-01-08
Mount Joy, PA

and there is a sticker with the legend on it about blinking lights



tp0d
yabbazooie
Premium
join:2001-02-13
Carnegie, PA
kudos:5

Have you changed the batteries in the thermostat? Thats the easiest fix. Need new batteries at the start of the heating season.

-j
--
if it aint broke, tweak it!!
currently on FiOS (kick aZZ!)


gmay10

join:2012-01-08
Mount Joy, PA

Just put in a new thermostat last month with brand new batteries. This never happens in the summer time with the AC- only in the winter with the gas furnace. This has been going on for a year or longer.



SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3
reply to gmay10

Well, I have never worked on a furnace with diagnostics that didn't have a way to view the LED through the blower panel. You never did say there was not a site glass, just that there is no way you can see the LED without taking off the panel. If there is a site glass, sometimes you have to literally put your eye right next to the site glass to see the LED because the site glass and the LED don't always line up with each other.

Do you feel comfortable holding in the door switch with the blower panel removed? If not, don't do it. If you do, just be careful because the blower might start running. Like I mentioned, you may have to hold the switch in for a while until the furnace locks out in order to see what the flash codes are showing.


gmay10

join:2012-01-08
Mount Joy, PA
reply to gmay10

I know it sounds weird and I have looked everywhere. I emailed the company my question and I am hoping to get a response today. I have taken the top and bottom panel off so I am not worried about doing it. There is also a piece of metal that is over the control board. I took that off a few weeks ago.

The furnace does not always go into lock down mode. It happens here and there. Yesterday it happened around 3 PM so I went down and turned it off and then turned it back on. It started up and didn't have any problems at all last night as I heard it come on a bunch of times in the middle of the night.



tp0d
yabbazooie
Premium
join:2001-02-13
Carnegie, PA
kudos:5

Intermittent fault sounds like a flame rod or an airswitch.

-j
--
if it aint broke, tweak it!!
currently on FiOS (kick aZZ!)



Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
reply to gmay10

You had this problem last year and called a service man to repair it.

Sounds like you need to call one again to repair the current problem.


gmay10

join:2012-01-08
Mount Joy, PA
reply to gmay10

I am about to go crazy!! I called the goodman company and they said that my model does not have a sight to see the blinking red light. Seh said that when that bottom panel comes off, it does nto reset the furnace. The light is pulsing which means everything is running normal. The thermostat says the heater is on. It is 62 degrees in here and should be 70. ANy thoughts. I justjust turned off the heater and that should reset it as I want to get some heat. But again, this only happens once everyweek or so. I am sure I would call someone to come out here to fix it and everyhting would be working fine!!
Thanks for all the help so far- I really appreciate it!



iknow

@optonline.net
reply to gmay10

You need to note the flash codes when the furnace is not working.(locked out).


gmay10

join:2012-01-08
Mount Joy, PA

The flash code is saying that the furnace is working as it should be. The red light is "pulsing" which means "running normal". The flash code is basically saying that everything is up and running. The thermostat says the furnace is on- it is not. Could it be a wiring issue which is why there is no rhyme or reason when the furnace does not work?



SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3

Do this. Post a photo of the furnace wiring diagram and the legend that explains the LED codes.

There's no guarantee we will be able to tell you what is happening when the furnace isn't working, but we can guide you through the controls that may be causing the issues you're having with the furnace. If you have a voltage tester, we can tell you where to check for voltage.



Irun Man
Spartan up
Premium
join:2002-10-18
Walden, NY
reply to gmay10

Is the ignitor lighting and are you getting any flame on startup?

If so and it only stays on for a few seconds, your flame sensor (the wire thing that was cleaned previously) is either misaligned or failed. I would check that part first, about a $30 item.

My gas furnace is also a Goodman:

»arnoldservice.com/

I bought an ignitor from these folks; they have flame sensors too.
--
I turned on my computer for this?



jack b
Gone Fishing
Premium,MVM
join:2000-09-08
Cape Cod
kudos:1

2 recommendations

reply to gmay10

Drill a small hole in the panel in a location where you will be able to see the control LED inside.



iknow

@optonline.net
reply to gmay10

it could be the control box is bad, it should have stored a fault code when it locks out, and it should never indicate it's running properly if the furnace is not operating properly, it has many sensors running to it, and one of them should have triggered fault codes.



Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
reply to gmay10

gmay10 It appears to me it's time for you to call a qualified service company.


HarryH3
Premium
join:2005-02-21
kudos:3
Reviews:
·Suddenlink

1 recommendation

reply to jack b

said by jack b:

Drill a small hole in the panel in a location where you will be able to see the control LED inside.

This!

I have two Goodman furnace/air handlers in my attic, circa early to mid 90s. Neither of them have (well, had) view ports to see the LED. In addition to the outer cover, they also have an inner cover so you can't see the control board even after removing the outer cover! Incredibly stupid design... And yes, opening the side panel turns off the power to the board, which does reset it. With my trusty drill and some clear packing tape to cover the holes, I can now see the LED's without removing the covers.


iknow

@optonline.net
reply to gmay10

here's the manual. »www.hvacpartsshop.com/Gmph050-3.pdf



SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3
reply to gmay10

said by gmay10:

The flash code is saying that the furnace is working as it should be. The red light is "pulsing" which means "running normal". The flash code is basically saying that everything is up and running. The thermostat says the furnace is on- it is not. Could it be a wiring issue which is why there is no rhyme or reason when the furnace does not work?

The "pulsing" blink you're seeing on the furnace control board, is that happening when the furnace is not working or when it is working? The reason I ask is because the manual (page 50) says the light should be "solid red for normal operation".

If the "pulsing" blink you're seeing is when the furnace is not working, I think what you're seeing is "1 Blink". For "1 Blink", the manual (page 51) points to several possibilities:

1. Gas Flow
2. Gas Pressure
3. Gas Valve
4. Flame Sensor


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

said by SandShark:

The "pulsing" blink you're seeing on the furnace control board, is that happening when the furnace is not working or when it is working? The reason I ask is because the manual (page 50) says the light should be "solid red for normal operation".

If the "pulsing" blink you're seeing is when the furnace is not working, I think what you're seeing is "1 Blink". For "1 Blink", the manual (page 51) points to several possibilities:

1. Gas Flow
2. Gas Pressure
3. Gas Valve
4. Flame Sensor

Installation and service must be performed by a qualified installer, service agency or the gas supplier.
pg 3 service manual

The 4 possible problems you posted are IMO something that novice untrained people should not be attempting to troubleshoot and repair especially #1, 2 and 3.

gmay10

join:2012-01-08
Mount Joy, PA
reply to HarryH3

said by HarryH3:

said by jack b:

Drill a small hole in the panel in a location where you will be able to see the control LED inside.

This!

I have two Goodman furnace/air handlers in my attic, circa early to mid 90s. Neither of them have (well, had) view ports to see the LED. In addition to the outer cover, they also have an inner cover so you can't see the control board even after removing the outer cover! Incredibly stupid design... And yes, opening the side panel turns off the power to the board, which does reset it. With my trusty drill and some clear packing tape to cover the holes, I can now see the LED's without removing the covers.

Yahtzee- this has been my problem. I can't see the blinking light due to no window and then a metal box covering the led light. I called the company and they said that taking off the bottom panel will not reset the buttons even though it turns the furnace off. Who knows if that is correct or not. The furnace has been working perfectly the last 24 hours. That is why this is such a problem. Some guy is going to come here and say everything looks fine to me.

gmay10

join:2012-01-08
Mount Joy, PA

Click for full size
Click for full size
Believe me, I am not touching anything that involves gas. I just want to make sure I can have an intelligent conversation or try to fix a small problem. I replaced my sensor piece last year- that is about as far as I would go in trying to fix this.
In the pic of the status light, I am clearly seeing that I am an idiot. I was literally reading the top line as a "pulse rate" is considered "normal operation". But after listening to you guys and using common sense, I guess I am in the 1 blink category which is out of my hands and into the hands of a professional. I actually called into a local home improvements show 2 weeks to discuss this problem and the guy said that it might be a gas flow/gas pressure problem since there was no rhyme or reason to when it would shut off. Let me know what you guys think.


jack b
Gone Fishing
Premium,MVM
join:2000-09-08
Cape Cod
kudos:1
reply to gmay10

Here's something you can do, with the top cover off start the furnace and watch when the burners first light off. The flame should immediately cross-over from the ignitor, one burner to the next, lighting all of them virtually instantaneously.

Watch multiple cycles, especially with the burners starting up cooled off, between cycles.

If there is any delay of all the burners lighting, they might need a cleaning. This dis-assembly and cleaning not something you should try to undertake yourself.
--
~Help Find a Cure for Cancer~
~Proud Member of Team Discovery ~



SandShark
Long may you run
Premium,MVM
join:2000-05-23
Santa Fe, TX
kudos:3
reply to gmay10

This is getting more confusing by the minute. The blink code legend for your furnace is not the same blink code legend in the manual "iknow" posted. So, if you're seeing a "pulse", that is normal.

I'd suggest doing what jack b See Profile suggested. To take it even further, you can also take off the blower panel and hold in the door switch while keeping an eye on the LED. Of course, for this to do any good, the furnace will have to malfunction during that time. If it operates normally, you're wasting your time.

The trick is the furnace needs to malfunction and you need to be able to see the blink codes. The suggestion to drill a hole in the blower compartment door and leave the control board cover off is a good one, as that's really the only way you're going to be able to see what the LED is telling you when the furnace malfunctions.